A2: Automatic Transmission/ Transaxle
When replacing the transmission extension housing bushing and seal, which of the following should also be inspected? A. output shaft bearing B. extension housing gasket C. driveshaft slip yoke D. speedometer drive O-ring
C. driveshaft slip yolk Since the driveshaft slip yoke rides on the extension housing bushing and seal, it should also be checked for wear and damage when the bushing and seal are replaced.
A multiple disc clutch is being assembled. Tech A says that all clutch plates should slide freely in the drum. Tech B says that all plates must be clean and dry when assembled. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech. A is correct because all plates should fit freely in the drum. Tech. B is wrong because the friction plates should be soaked in clean transmission fluid for at least 20min. prior to clutch assembly. Dry, they will overheat and burn.
Tech A says that converter end-play is checked to determine the combined lateral movement (converter installed) of the turbine and stator. Tech. B says that converter end-play is checked with a feeler gauge. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only Tech B is wrong because converter end-play is checked with a special tool and a dial indicator. The tool is inserted into the converter hub until it bottoms, then the dial indicator is attached to the tool.
Tech A says that the Engine Coolant Temp (ECT) sensor is primarily used to prevent Torque Converter Clutch (TCC) lockup while the engine is cold. Tech B says that, when testing the sensor, the resistance should increase as the temp increases. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only The ECT sensor is primarily used as an input signal for TCC application. The increased load of the TCC is undesirable when the engine is cold due to the additional load that it places on the engine. Tech B is wrong because the ECT is an NTC (negative temp coefficient) thermistor. As temp increases, the resistance of the ECT becomes lower.
When inspecting a planetary gear set, tech A says that the pinion gear side clearance should be checked with a feeler gauge. Tech B says that if any part of the planetary gear set fails inspection, the entire gear set must be replaced. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only The pinion gear side clearance should be measured with a feeler gauge and compared with the manufacturer's specs. Tech B is wrong because some planetary gearsets can be rebuilt with new pinion gears, thrust washers, pins and needle roller bearings.
A front wheel drive vehicle with an automatic transaxle has excessive vibration. Technician A says that the vibration could be caused by worn engine/ transaxle mounts. Technician B says that the vibration could be caused by a misaligned engine/ transaxle subframe. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. both A and B. Worn engine and transaxle mounts can cause vibration, but driveline vibration can also be caused by and engine/transaxle subframe that is damaged or not properly positioned and secured to the vehicle.
All of the following should be performed during a preliminary transmission inspection EXCEPT: A. check Transmission fluid level B. visually check wiring and electrical connections C. check clutches and servos with air pressure D. check for fluid leaks
C. check clutches and servos with air pressure Air pressure tests should not be performed until all preliminary inspections, road testing and pressure testing has been performed. All of the other choices are checks that would be made during a preliminary inspection.
What clearance is being checked on the transmission oil pump (image shown below)? A. gear-to-pocket clearance B. inner-to-outer gear tip clearance C. gear-to-pump body clearance D. input shaft end-play
C. gear-to-pump body clearance End-play is usually measured with a dial indicator and input shaft end-play should be measured before the oil pump is removed. Gear-to-pocket clearance and inner-to-outer gear tip clearance can be measured with a feeler gauge alone. Gear-to-pump body side clearance is measured using a straightedge and a feeler gauge.
When disassembling a transmission, which of the following checks should be made before removing the trans oil pump? A. torque converter end-play B. input shaft preload C. input shaft end-play D. input shaft runout
C. input shaft end-play Before the trans pump is removed, the input shaft end-play must be measured. Insufficient end-play will cause binding and drag, while excessive end-play can cause noise and parts damage. If the end-play is incorrect, thrust washers of different thickness can be substituted during the rebuild to restore end-play to specification.
A transmission cooler suspected of being plugged is being tested. A hose is connected between the cooler outlet and an open container and the vehicle is run at idle for 20 seconds and then turned off. How much fluid should be in the container if the cooler is not plugged? A. cup B. pint C. quart D. gallon
C. quart If the cooler is not plugged there should be a quart in the container. However, before condemning the cooler, disconnect the inlet line from the cooler and repeat the test to see if there is enough flow from the transmission. If there is, the cooler is plugged. If there still isn't enough flow, check the line back to the trans for kinks or other damage. If the line is OK, then there is a problem with the transmission.
All of the following sensors provide input for transmission control to the Powertrain Control Module (PCM) EXCEPT: A. Intake Air Temperature (IAT) sensor B. Throttle Position (TP) sensor C. Engine Coolant Temperature (ECT) sensor D. Mass Air Flow (MAF) sensor
A. The PCM recieves input from the MAF sensor that informs the computer of the load under which the engine is operating. The MAF sensor directly measures the mass of the air flowing into the engine. For transmission control purposes, the PCM uses this information for mainline pressure control, shift timing and TCC application. The ECT sensor signals the PCM regarding engine coolant temperature, and therefore the temperature under which the engine is operating. The PCM uses this information primarily for TCC application. The TP sensor converts driver input in the form of accelerator pedal position to a voltage signal to the PCM. The PCM uses this information for shift scheduling, transmission line pressure control and TCC control. The IAT sensor provides input to the PCM for engine control but not transmission control. The IAT sensor advises the PCM of changes in intake air temperature ( and therefore air density). As intake air temperature varies, the PCM, by monitoring the voltage change, adjusts the amount of fuel injection according to the air temperature.
When testing a Torque Converter Clutch (TCC) hydraulic circuit, a hydraulic pressure gauge is observed while applying the accelerator with the transmission in Drive range, until the 2-3 upshift occurs and the indicated speed is approx. 50 mph. If the TCC control valve is operating, how much pressure drop should be seen on the gauge? A. 5-10psi B. 10-15psi C. 15-20psi D. 20-25psi
A. 5-10psi If the TCC control valve is operating, there should be a momentary drop of 5-10psi on the gauge
The MIL was illuminated on the dash of a 2008 Ford Ranger. A scan tool was connected to the DLC and the following DTCs were retrieved: -P0112- TP Sensor -P0731- Shift Solenoid A, no first gear -P0750- Shift Solenoid A, solenoid circuit failure -P1714- Shift Solenoid A, solenoid mechanical failure Which DTC should be checked first? A. P0112 B. P0731 C. P0750 D. P1714
A. P0112 Engine performance may affect trans performance. Since the TP sensor affects engine performance and also provides an input to the computer for trans control, it should be checked and repaired before
When retrieving stored codes from an electronic transmission control system, a hard fault is found regarding the Throttle Position (TP) sensor circuit. Tech A says that the TP sensor circuit should be tested. Tech B says that since it is a hard fault, the TP sensor must be replaced. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only A DTC does not indicate that there is a problem with a particular component just that there is a problem with the circuit that includes the component. The problem could be an open circuit caused by a broken wire, high resistance due to dirty, corroded or loose terminals in a connector, or a short circuit caused by worn wiring insulation. The diagnostic info. in the manufacturer's code charts will detail the voltage, resistance and current flow checks that should be made to identify the failure. Tech B is also wrong because a hard fault only means that the DTC reappeared during a road test after being cleared from the computer's memory.
The MAP sensor voltage on a vehicle is measured with the engine running at idle and found to be almost 5 volts. Tech A says that this voltage is too high for idle speed. Tech B says that this voltage will cause the trans to shift too early. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only A high voltage reading at the MAP sensor should indicate atmospheric pressure inside the intake manifold, which should only happen when the engine is off or at WOT (Wide Open Throttle). Since the engine is running, the PCM will think the engine is at WOT, causing late, hard shifts.
A transmission was just replaced several days ago and now the vehicle is back with a check engine light and harsh shifting. Tech A says that a wiring harness that did not get properly routed during trans installation could cause this. Tech B says that fuel lines did not get bolted back into their brackets during transmission install could cause this. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only A wiring harness that did not get properly routed during trans install could have gotten pinched, melted, or rubbed through on another component. This could cause a short circuit, a blown fuse, an open circuit, etc. Any of those conditions could cause a check engine light and a transmission that defaults to max line pressure. This would result in the harsh shifting complaint. Tech B is wrong. It is highly unlikely that an unsecured fuel line would cause this problem. The only exception would be if it were to rub on a wire harness and cause an electrical circuit problem.
A trans. is experiencing a harsh 2-3 upshift with no DTCs. Tech A says that an accumulator with a stuck piston could cause this problem. Tech B says that a scratched clutch piston bore could cause this. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only Accumulator's job is to provide cushioning for trans upshifts, downshifts, and garage shifts. if the accumulator piston is stuck in it's bore, it will not be able to provide the desired cushioning. Tech B is wrong. A scratched piston bore for the mutli-plate clutch used for third gear would cause a delayed, and possibly soft, upshift. This is because of fluid leaking past the clutch piston seal in the area of the scratched piston bore.
Tech A says that transaxle differential side and pinion gears should be replaced if they are scuffed or have broken teeth. Tech B says that when the differential is assembled, side gear end-play should be checked with a feeler gauge and shimmed accordingly. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only Differential side and pinion gears should be replaced if these defects are found. Tech B is wrong because side gear end-play is checked with a dial indicator and corrected with different thickness washers.
When inspecting a transmission band, Tech A says that the corresponding drum should also be inspected and replaced if it is very rough or scored. Tech B says that when a band is replaced, the drum should be polished for proper band operation. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only Drum should be slightly rough in order to break in the new band.
Tech A says that the first step in trans diagnosis is listening to the customer's complaint. Tech B says that diagnosis should begin with a road test. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only Save time, listen to the customer. Make sure the normal operation of current vehicle is not just simply different than one previously owned.
A torque converter is about to be installed in the transmission. Tech A says the torque converter should be installed with the input in a vertical position. Tech B says the torque converter should be installed with the input shaft in the horizontal position. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only To avoid trans pump bushing/ bearing damage, front seal damage, and torque converter hub damage, the torque converter should be installed with the trans input shaft (turbine shaft) in the vertical position. Tech B is wrong because it is very likely that a scratched or damaged pump bushing and seal will result from installing the torque converter with the input shaft in the horizontal position
Tech A says the fluid level on some automatic trans is checked by removing a level control plug. Tech B says the fluid level should be checked on these trans with the engine off. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
A. Tech A only refer to manufacturers specs for whether engine should be running or not
All of the following methods can be used to remove old bushings from a trans case EXCEPT: A. cut out with a torch B. driven out with a suitable driver C. cut and pulled out D. pulled with a slide hammer and special adapter
A. cut out with torch using a torch may damage the case. All other examples are correct
All of the following clutch components are used by manufacturers to adjust clutch pack clearance EXCEPT: A. drum B. steel plate C. pressure plate D. snap ring
A. drum Clutch drum is not used to adjust clutch pack clearance. Clutch pack clearance can be adjusted using snap rings, pressure plates, and steel plates of various thickness; refer to the manufacturer's service information for the exact method.
All of the following are methods of removing the oil pump from the transmission case EXCEPT: A. pressing on the output shaft B. slide hammer C. puller D. prying on the geartrain
A. pressing on the output shaft The pump is a tight fit in the case and must be removed using slide hammers, special pullers or by prying on the gear train.
All of the following are true statements regarding trans fluid and filter changes EXCEPT: A. If the transmission oil pan holes are distorted, place the flange on a flat surface and tap down the raised area with a hammer B. The filter should be installed using a new gasket or O-ring C. The trans fluid is drained by removing the drain plug D. If the pan bolts have compressible conical washers, any bolts with the washers reversed must be replaced.
C. Most transmission oil pans do not have drain plugs, so the pan must be removed to drain the fluid. All of the other statements are true regarding fluid and filter changes
A vehicle with an automatic transmission is experiencing harsh upshifts and downshifts with no DTCs. During the line pressure test, the line pressure, as commanded by a scan tool, does not match the pressures shown on a pressure gauge. Technician A says the pressure control (PC) solenoid circuits should be inspected. Technician B says the Pressure Control (PC) electrical circuits are not the problem. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. If the PC solenoid electrical circuits had and electrical problem, a DTC would set. The problem is likely a mechanical or hydraulic issue. Eventually a "performance" DTC will set indicating a problem with the performance of the mechanical or hydraulic system. An example would be a stuck pressure regulator valve.
A voltage generating Vehicle Speed Sensor (VSS) is being tested. Tech A says that the transmission shaft should be rotated and the DC voltage output checked. Tech B says that the sensor resistance should be checked. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B is correct because the amount of resistance in a VSS can be checked with and ohmeter. Tech A is incorrect because when VSS voltage is checked, the meter should be on the AC setting. The VSS is a permanent magnet generator that produces and AC signal. When checked with a lab scope, this signal will appear as a sign wave pattern.
Automatic transmissions use either vane or gear type oil pumps. All of the following apply to both pump designs EXCEPT: A. They both pump fluid as soon as the engine starts. B. They both provide a variable level of output volume. C. They can be mounted at the front of the transmission case. D. They can be driven by the torque converter hub.
B. The fixed displacement (gear-type) pump always moves the same amount of oil regardless of the transmission's needs. In contrast, the variable displacement pump (vane-type) adjusts the volume of oil output through the use of a slider valve.
A tech is air checking a clutch assembly and notices a slight hissing sound from the clutch piston area. Tech A says that this is normal for pistons in housings that rotate. Tech B says that this is normal for pistons in housings that do not rotate. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only Tech A is wrong. Most clutch pistons in housings that rotate while driving have a check ball or other device to retain fluid pressure (and air pressure) while the clutch is applied. When the hydraulic pressure for the clutch piston is released, centrifugal force will cause the check ball to roll away from a fixed orifice hole and allow the unpressurized fluid to escape. If the check ball does not seat properly when air pressure is applied, it will make a hissing sound. Tech B is correct. Most pistons in housings that do not rotate while driving have a fixed orifice at the 12 o'clock position. This orifice will always leak a small amount of pressurized fluid. It will also leak compressed air making a hissing sound during a pressure test.
Tech A says that while assembling an automatic transmission, grease or petroleum jelly should be used to hold thrust washers in position. Tech B says that all bushings and shafts should be lubricated with trans. assembly lube or trans. fluid. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only Thrust washers can be held in place using assembly lube or petroleum jelly to keep them from falling out of position but grease should never be used, as it may not mix with the trans fluid
Tech A says that transmission fluid that is not bright red has broken down and must be changed. Tech B says that it is oxidation at high temperatures that causes trans fluid break down. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only Trans fluid is dyed red in order to distinguish it from engine oil and other fluids, but as the fluid ages, its color darkens. This color change results from normal use and it not a sign of fluid breakdown. If varnish is found on the dipstick accompanied by a varnish like odor, that's a sign of trans fluid breakdown. The varnish is a by-product of the oxidized fluid and is typically the result of severe use like trailering and/ or fluid change neglect.
Tech A says that pink colored transmission fluid is evidence of overfilling and the pink color is caused by aeration of the fluid. Tech B says that pink colored transmission fluid is caused by coolant mixing with the transmission fluid due to a leak in the transmission cooler. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only Trans fluid that is pink and has a milky consistency indicates that the trans cooler in the radiator has ruptured, contaminating the fluid with coolant.
The fluid level is checked on a cold automatic transaxle and is found to be above the Full Hot mark. Tech A says that the unit is overfilled, since the fluid will expand as the temp increases, making the fluid level rise. Tech B says the fluid level may fall as the unit warms up, and the only way to get an accurate reading is to check the fluid when it's temp is within the range specified by the manufacturer. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only When checking fluid level, it is important to observe the manufacturer's specified fluid temp range. Many trans have a thermostatic element that restricts fluid flow at certain temps. These elements contain temp sensitive strips of metal that react to fluid temp changes and open or close a fluid passage. Checking the fluid level at the wrong temp could produce and ino
When performing a trans stall test, Tech A says that the accelerator should be held to the floor no longer than 10 seconds. Tech B says that the trans should be placed in Neutral and the engine run at fast idle for 30-60 seconds, in between each test, to cool the torque converter. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only When performing a trans stall test, the accelerator should be held to the floor for no longer than 5 seconds.
Tech A says that all power should be removed from a circuit before testing the circuit with an ammeter. Tech B says that all power should be removed from a circuit with an ohmmeter. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
B. Tech B only When using an ohmmeter, all power should be removed from the circuit. Power to the circuit is necessary when testing a circuit with and ammeter.
When pressure testing a transmission, line pressure is compared with the pressure in each of the clutch circuits. Which specification should be used to determine whether a sealing problem exists? A. if the difference between line pressure and a clutch circuit pressure is greater than 5psi B. if the difference between line pressure and a clutch circuit pressure is greater than 10psi C. if the difference between line pressure and a clutch circuit pressure is greater than 15psi D. if the difference between line pressure and a clutch circuit pressure is greater than 20psi
B. if the difference between line pressure and a clutch circuit pressure is greater than 10psi check the oil pressure difference between line pressure and second, third and fourth clutch oil pressure. If the difference between line pressure and any of the clutch circuits is greater than 10psi, there is a sealing problem in that circuit.
When conducting a road test, which two sets of the vehicle manufacturer's specifications should be referred to? A. fluid pressure and shift speed B. shift speed and clutch and band application C. clutch and band application and fluid pressure D. fluid pressure and fluid temperature
B. shift speed and clutch and band application The shift timing and shift quality at various throttle opening positions should be checked and compared with the manufacturer's shift speed specifications. A clutch and band application chart should be used to determine what planetary gear control devices are engaged in each gear position.
A customer with a vehicle equipped with an electronically- controlled trans has a complaint of harsh shift engagement. This could be caused by a malfunction in any of the following circuits EXCEPT: A. Throttle Position (TP) sensor circuit B. Trans Range (TR) sensor circuit C. Brake On/ Off (BOO) switch circuit D. Turbine Shaft Speed (TSS) sensor circuit
C. BOO switch circuit The Brake on/off switch signals to the PCM that the brake is applied and the Torque Converter Clutch should be disengaged. A malfunction in any of the other circuits listed could cause a complaint of harsh shifting.
A vehicle with an automatic transmission has a whining noise that increases with engine speed. Technician A says that this could be caused by the transmission oil pump. Tech B says that this could be caused by low fluid level. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A whining noise at idle that increases with engine speed could be caused bu the transmission pump or low fluid level
Tech A says that trans bearings must roll freely and smoothly or they can make noise and fail. Tech B says that trans bearings and bushings should be lubricated with trans fluid. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B
An electrical circuit is being tested using a Digital Multimeter (DMM). When measuring voltage in the circuit, Tech A says that the meter should be connected in parallel. When measuring amperage, Tech B says that the meter should be connected in series. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B A voltmeter is always connected in parallel when making a voltage check of a circuit. An ammeter is connected in series with the circuit, so all the current passing through passes through the ammeter.
Tech A says that if the fluid level is correct but the line pressure is low, a worn or damaged oil pump may be indicated. Tech B says that low line pressures can be caused by a clogged filter, internal leaks or a faulty pressure regulator. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Any pressure reading outside specs indicates a problem. Normally when the fluid level is correct and the pressures are low, internal leaks, a clogged filter, low pump output or a faulty pressure regulator valve is the cause. Pressure that builds up at the wrong time or is not high enough, indicates leaking seals or sticking valves.
Tech A says that the resistance of trans actuator solenoids should be checked. Tech B says that their mechanical operation should also be checked. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Both can be checked. To check resistance, disconnect the wiring connector from the solenoid and connect the DMM leads to the solenoid terminals. Compare the resistance reading on the DMM with manufacturer's specifications. Then move one of the DMM leads to the solenoid body or base to check for a ground circuit. A two-wire solenoid will not be grounded through the solenoid case, so the DMM reading should be infinity. A single wire solenoid is grounded through the solenoid case, so in this case there should be continuity. A solenoid is an electromagnet and can attract small metal particles, which could cause the solenoid to stick or bind, so the mechanical operation should also be checked. Blow air through the solenoid when it is energized and deenergized. A normally closed solenoid should allow air to pass when energized but block air flow when it is not energized. A normally open solenoid should allow air to pass when it is not energized but block airflow when it is energized.
Tech A says leaking intake manifold gaskets can cause delayed and harsh shifts. Tech B says worn valve guides can cause delayed and harsh shifts. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Both leaking intake manifold gaskets and worn valve guides can cause a lean condition and low manifold vacuum. Low engine vacuum will make a vacuum modulator or electronic control system indicate an engine load condition that does not exist, causing delayed and harsh shifts.
The transaxle on a front wheel drive vehicle will not shift into 3rd gear. Tech A says that the problem could be corrosion at the Powertrain Control Moduel (PCM) connector. Tech B says that the problem could be a broken wire in a shift solenoid circuit. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Corrosion would cause a poor connection at the PCM and would prevent the actuator signal from reaching the shift solenoid. A broken wire would cause an open circuit in the shift solenoid circuit and also prevent the PCM signal from reaching the shift solenoid.
Tech A says that a malfunctioning Torque Converter Clutch (TCC) can cause decreased fuel economy. Tech B says that a malfunctioning TCC can cause decreased trans fluid life. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Even while operating at peak efficiency, a torque converter experiences up to 10% energy loss (slip) when it reaches the coupling point. This wasted energy is dissipated in the form of heat created by the slippage between the impeller and the turbine. It is this heat source that poses the greatest threat to the life of the transmission fluid. The TCC is a device that captures this otherwise lost energy. By doing so, the TCC increases fuel economy, prolongs the life of the transmission fluid and also extends engine life by keeping rpm lower at higher vehicle speeds.
After removing a trans from a vehicle, inspections should be performed. Tech A says the rear main seal and engine block core plugs should be inspected for leakage. Tech B says the flex plate and trans alignment dowel pins should be inspected for damage. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Inspect anything that is easily accessible with the trans removed.
A trans was just replaced. Tech A says to flush the trans cooler before connecting the cooler lines. Tech B says to clear the adaptive learning memory values with a scan tool before performing a road test. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Old trans fluid will wipe out the new transmission. You must clear the TCM for the new transmission to operate properly
Tech A says that transaxle final drive side bearing preload is typically measured with an inch pound torque wrench. Tech B says that all end-play must be removed when adjusting bearing preload. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Preload exists when all end-play between bearing rollers and races has been removed and a load is placed against the inner or outer race, such that there is a measurable drag when a shaft or rotating component turns. This drag is usually measured with an inch pound torque wrench and the specification is for the drag recorded while the torque wrench turns, not what was required to begin motion.
An Engine Coolant Temperature (ECT) sensor is being tested. Tech A says that a negative coefficient temp sensor should be tested by checking the voltage drop across the sensor. Tech B says that the resistance should be checked on this type of sensor. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Resistance varies inversely with temp. on a negative coefficient temp. sensor. More voltage is dropped across the sensor when it is cold, and less when hot. The PCM monitors the voltage change and adjusts engine and transmission actuators accordingly. The sensor's function can also be checked by measuring the resistance between the sensor terminals using a DMM and comparing with the manufacturer's specification for resistance at the sensor's particular temperature. The sensor can also be cooled and heated in water and the resistance readings compared with specifications for various temps
Tech A says that a free-wheeling stator clutch will cause poor vehicle acceleration. Tech B says that a free-wheeling stator clutch will cause stall speed to be too low. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Since the stator clutch is supposed to lock the stator in place until the converter's coupling speed is reached, a free-wheeling stator clutch would prevent the torque multiplication necessary to properly launch the vehicle. This would appear as a lack of power. If stall speed is too low, the problem could also be a free-wheeling stator clutch. Since the stator clutch locks below converter coupling speed, it allows the stator to deflect the oil back to the turbine. If the stator clutch freewheels in both directions, the turbine oil will now be thrown back at the impeller, hindering it's rotation. This condition will prevent the engine from reaching a normal stall speed.
The Malfunction Indicator Light (MIL) is illuminated on the dash of a vehicle with an electronically controlled transaxle. When a scan tool is connected to the Data Link Connector (DLC), it reveals that there is a Diagnostic Trouble Code (DTC) that corresponds to a transmission control system circuit. Tech A says that the wiring in the circuit should be inspected before performing any tests. Tech B says that the battery voltage should be checked. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Tech A is right because faulty wiring and poor connections can cause a variety of shifting problems. Tech B is also correct because before concentrating on the circuit, you should make sure the power and ground connections are good. The voltage at the battery, PCM or TCM and trans power relay (if equipped) should be 12.6 volts with the engine off and 13.6-15.0 volts with the engine running.
Two Techs are discussing differential oil seal replacement on an automatic transaxle. Tech A says that a pry bar or slide hammer/puller can be used on most vehicles to remove the halfshaft. Tech B says the axle shaft should not be pulled on to remove the halfshaft. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Tech A is right because on most vehicles there is a circlip in a groove on the end of the inner CV-joint stub shaft, which retains the inner CV-joint to the differential side gear. With this design, a prybar or slide hammer/puller is used to release the inboard stub shaft from the differential side gear, so that the halfshaft can be removed. Tech B is right because the axle shaft should never be pulled on in an effort to separate the stub shaft from the differential, as the inboard CV-joint can be pulled apart.
The Torque Converter Clutch (TCC) on an electronically-controlled trans is being discussed. Tech A says that the Powertrain Control Module (PCM) uses inputs from the Vehicle Speed Sensor(VSS) and Engine Coolant Temp (ECT) sensor to engage the TCC. Tech B says the PCM uses inputs from the Throttle Position (TP) sensor and Brake On/Off (BOO) switch to disengage the TCC. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B The engine must be above a certain temperature and the vehicle speed above a certain mph for TCC application, so Tech A is right. When the driver steps on the accelerator or the brake pedal, the PCM uses signals from the TP sensor and BOO sensor respectively, to disengage the TCC, so Tech B is right.
Tech A says that an incorrectly adjusted manual shift linkage can cause the manual valve to leak pressure into the wrong hydraulic circuit. Tech B says that an incorrectly adjusted manual shift linkage can cause vehicle creep in neutral. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B When the gear selector is moved, the manual shift linkage must exactly position the valve in it's bore. If the linkage is improperly adjusted, hydraulic circuits may be opened to line pressure when they should be closed. This could cause a clutch to partially apply and cause the vehicle to creep.
A front wheel drive vehicle creeps in Neutral and shifts erratically. Tech A says that the cause could be worn or broken power train mounts. Tech B says the cause could be a damaged or improperly positioned subframe. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
C. Both A and B Worn powertrain mounts can allow excessive powertrain movement. This excessive movement can adversely affect manual shift and TV linkages, possibly resulting in the inability to shift into gear or incorrect shift timing and quality. Many vehicles have the engine and transaxle assembly, suspension and/or steering components mounted to removable subframes or crossmembers. If the subframe or crossmember is damaged or not properly positioned and secured to the vehicle, this can result in symptoms similar to those caused by worn mounts.
Under which of the following conditions is the transmission range switch usually adjusted? A. Range Selector in Park B. Range Selector in Reverse C. Range Selector in Neutral D. Range Selector in Drive
C. Neutral The transmission range sensor (TR) or Transmission Internal Mode switch (IMS) is typically adjusted to a set position with the transmission range selector in the Neutral position
When testing computer-controlled systems, a Digital Multimeter (DMM) should be used with an input impedance of at least: A. 10K ohms B. 100k ohms C. 1 mega-ohm D. 10 mega-ohms
D. For maximum protection to the computer-controlled system or any electronic circuit, it is best to use at least a 10-megaohm impedance DMM.
Tech A says that, when testing trans actuator solenoids, a normally closed solenoid should block air flow when energized. Tech B says that a normally open solenoid should allow air flow when energized. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
D. Neither A nor B A normally closed solenoid should allow air to pass when energized but block air flow when it is not energized. A normally open solenoid should allow air to pass when it is not energized but block air flow when it is energized.
Tech A says that a blackish oil film found in a transmission oil pan after removal is evidence that the transmission overheated. Tech B says that loose black material found in a transmission oil pan after removal is evidence of excessive wear or damage to gears, bearings and thrust washers. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
D. Neither A nor B Tech A is wrong because a blackish oil film found in a transmission oil pan after draining the fluid is considered normal. Tech B is wrong because if the pan contains loose black material that smells burned, this is evidence of burned lining material from a slipping clutch or band.
The MIL was illuminated on the dash of a 2008 Ford Ranger. A scan tool was connected to the DLC and the following DTCs were retrieved: -P0112- TP Sensor -P0731- Shift Solenoid A, no first gear -P0750- Shift Solenoid A, solenoid circuit failure -P1714- Shift Solenoid A, solenoid mechanical failure Which DTC is manufacturer specific? A. P0112 B. P0731 C. P0750 D. P1714
D. P1714 The origin of the code is represented by the first number in a DTC. Codes from Society of Automotive Engineers (SAE) start with 0. These codes are known as generic DTCs because they are the same for every vehicle. Manufacturer specific codes start with 1. These DTCs are part of the manufacturer's enhanced diagnostic software and vary between brands.
A customer has a complaint of poor fuel economy. During inspection the trans fluid is found to be brown and smells burned. These symptoms could be caused by a malfunction in any of the following circuits EXCEPT: A. Engine Coolant Temp (ECT) sensor circuit B. Vehicle Speed Sensor (VSS) circuit C. Torque Converter Clutch (TCC) circuit D. Transmission Range (TR) sensor circuit
D. Transmission Range (TR) sensor circuit A torque converter clutch (TCC) that is not engaging would cause poor fuel economy and burned trans fluid. If the TCC does not engage, there will be some slippage when the converter reaches the coupling point. This slippage results in heat, which breaks down the trans fluid, and also causes poor fuel mileage because the engine operates at a higher rpm. A malfunction in the ECT sensor, VSS or TCC solenoid circuits could cause the TCC not to engage. A malfunction in the TR sensor circuit would not affect TCC operation.
During disassembly and inspection of a Continuously Variable Transaxle (CVT), scratches are found on the pulley sheaves and a thin feeler gauge like piece of steel is found near the pulleys. What could cause this? A. high primary pulley pressure B. high secondary pulley pressure C. pressure switch malfunction D. failed push belt ring pack
D. failed push belt ring pack CVT push belt ring pack is made up of many layers of thin steel "Feeler Gauge" type rings. If a piece of a ring pack cracked and broke, a piece of the ring pack could come out of the push belt, scratch the pulley sheaves, and fall into the case. Answers A, B, and C will not cause a ring pack failure. Ring packs typically fail because of abusive driving, high mileage, and improper fluid.
All of the following could cause a trans to overheat EXCEPT: A. clogged oil cooler B. faulty Torque Converter Clutch (TCC) C. seized converter stator D. freewheeling converter stator
D. freewheeling converter stator A plugged transmission oil cooler will restrict flow and not remove enough heat from the trans fluid. A TCC that does not lock up will allow slippage between the torque converter impeller and turbine, creating too much heat for the cooler to dissipate. A seized stator will continue to redirect fluid flow within the converter and torque multiplication will continue after it is needed, overheating the transmission fluid. A freewheeling stator will cause a lack of torque multiplication and sluggish low speed performance, but not cause the trans to overheat.
All of the following are true statements regarding transmission seals EXCEPT: A. Open end metal sealing rings should have a small gap between the ends to allow for expansion. B. Locking end rings should be locked together after installation. C. Scarf cut Teflon sealing rings are installed so that the ends are square with each other. D. Solid Teflon sealing rings should be installed by hand.
D. is incorrect Solid Teflon sealing rings require a special tool for installation. The tool stretches the seal, pushes it into place and then compresses it to the proper size. All the other statements are true regarding transmission seals.
All of the following are methods for detecting external trans fluid leaks EXCEPT: A. external cleaning followed by visual inspection B. aerosol talcum powder C. black light and fluorescent dye D. pressure test
D. pressure test Pressure testing is to check hydraulic fluid pressure to see if it's at the proper level based on range selection and RPM, not to find external leaks. All of the other methods are commonly used to detect leaks.
After assembling a multiple-disc clutch, a tech should do which of the following? A. install it in the transmission B. soak it in clean trans fluid for at least 20 minutes prior to assembly C. test it with hydraulic pressure D. test it with air pressure
D. test it with air pressure Once the clutch is assembled, apply approximately 30psi air pressure to the clutch apply hole to check clutch operation. The piston should compress the clutch plates when air is applied while leaking no air, and the piston should release when air pressure is released.
All of the following are true statements regarding valve body service EXCEPT: A. check balls can be held in place with petroleum jelly during valve body installation B. the location of valve body retaining bolts should be noted as they may be different sizes and lengths C. new valve body gaskets should be compared with the old ones to ensure the correct ones are installed D. valve body bolts should be torqued to specification, gradually and evenly, beginning at the outer edge and working towards the center of the valve body in a spiral pattern
D. valve body bolts should be torqued to specification, gradually and evenly, beginning at the outer edge and working towards the center of the valve body in a spiral pattern D. is incorrect because as a general rule, the valve body bolts should be torqued beginning in the center and working towards the outer edge of the valve body in a spiral pattern. However, if the manufacturer recommends a torque sequence, then that sequence should be followed
All of the following clearances should be checked when servicing a gerotor-type transmission oil pump EXCEPT: A. gear-to-pocket clearance B. rotor-to-pump body side clearance C. tip clearance D. vane clearance
D. vane clearance Gerotor pumps do not contain vanes, which are only used on vane pumps. All the other clearances should be measured when servicing a rotor pump.
Under which of the following scenarios will the Torque Converter Clutch (TCC) activate? A. when Engine Coolant Temperature (ECT) sensor resistance is high B. when ECT sensor signal voltage is high C. when the Brake On/Off (BOO) switch circuit is complete D. when Trans Fluid Temp (TFT) sensor resistance is low
D. when Trans Fluid Temp (TFT) sensor resistance is low The TCC will not activate until the engine coolant and trans fluid temps reach a certain operating temp. The increased load of the TCC is undesirable when the engine and trans are cold due to the additional load that it places on them. Both the ECT and TFT sensors are NTC thermistors, so as the temp of these sensors increases, their resistance becomes lower. This action causes a voltage drop at the computer's signal terminal, which is interpreted as higher temp. Therefore, answers A and B are wrong because high sensor resistance and signal voltage would correspond to cold temps. Answer C is also wrong because the brake On/Off switch circuit is complete when the brakes are applied, and the PCM is signaled to disengage the TCC.
To achieve the output forces shown in the illustration above, how much applying force should be used? A. 5lbs B. 10lbs C. 15lbs D. 20lbs
The correct answer is A. Force / Area = Pressure. To achieve the output forces shown, 10psi must be applied to each Piston 10/1=10 20/2=10 and 25/2.5=10 to generate 10 psi in the system, 5lbs of pressure must be applied to the 0.5 in. piston because pressure x area = Force 10 x 0.5 = 5.
The Malfunction Indicator Light (MIL) is illuminated on a vehicle presented for service and the customer complains of transmission problems. A scan tool reveals that there are both engine and transmission related Diagnostic Trouble Codes (DTCs). Technician A says that the engine related DTCs should be serviced first. Technician B says that engine related DTCs have no effect on transmission performance. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
The correct answer is A. Technician A is correct because proper transmission diagnosis requires that the engine be in good running order. This is important because sometimes symptoms that are caused by a poor running engine can be mistakenly attributed to the transmission. Always make sure the engine is operating properly and if needed, perform all necessary repairs before proceeding with transmission diagnosis. This would include servicing engine related DTCs.
Technician A says that, when checking for voltage in a sensor circuit of an electronic transmission control system, a test light should be used. Technician B says that a known good ground should be touched before replacing the sensor. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
The correct answer is B. A test light should not be used when trouble shooting computer related circuits (unless specifically instructed to do so) as its current draw could damage the sensor and/ or computer. Some computer circuits are designed to carry very small amounts of current, so a high- impedence ( over 10 megaohms) digital meter should be used to check voltage in these circuits. Technician B is right because, in order to prevent damage from electrostatic discharge, you should always touch a known good ground before handling an electronic component.
Technician A says that the illustration above shows the correct way to measure the clearance of multiple disc clutch assembly. Technician B says if clearance is incorrect it can be restored using a different thickness snap ring. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B
The correct answer is C, both technicians are right. The clearance on some clutch packs can be adjusted using snap rings of varying thickness. Clearance is determined by pushing down on the pressure plate and checking the distance between the plate and snap ring with a feeler gauge. The thickness of the snap ring is then measured. The needed thickness is calculated by comparing the clearance measurement with the manufacturer's specifications and adding or subtracting as required.
