UTI AT-12 202 Hybrid-Introduction to Drivability
Reading the second DTC digit, what does the it specify about the DTC?
- 0: Generic (SAE) DTC - 1: Manufacturer specific DTC - 2: Generic (SAE) DTC - 3: Manufacturer specific DTC or generic DTC
What advantage do Electronic Fuel Injection (EFI) system provide over Carburetor fuel delivery systems?
- Better engine performance - Quick response during throttle changes - Easier starting - BEtter operation at extremely high or low temperatures - Longer maintenance intervals - Better gas mileage - Lower tailpipe emissions
What is the purpose of Idle Air Control?
- Controls engine idle speed - Regulates air bypassing the throttle plate - adapts to engine load -
What is the purpose of the Camshaft Position sensor (C.M.P) in regards to the ECM?
- Determines position of camshaft - Used for sequential fuel injection to determine which cylinder is on the compression stroke. - Typically a pulse generator or Hall-effect sensor - If sensor fails, the ECM will instead switch to batch or bamk fire to keep the engine running.
What is the purpose of the Crankshaft Position Sensor (C.K.P) in regards to the ECM?
- Determnine position and speed of crankshaft - Determine when to fire the injectors and spark plugs. - Used for misfire detection in OBD 2 vehicles. - Typically a Hall-effect sensor, using a slotted or toothed reluctor wheel mounted on the crankshaft or flywheel.
What conditions may cause a "Clear Flood Mode" and what can you do to resolve it?
- Excessive gas in the combustion chamber - By depressing the gas pedal, you can turn over the engine to remove excessive fuel, and after turning over the fuel will be exhausted or removed. The vehicle can then typically start again.
What are the characteristics of the Turbocharger air induction system?
- Exhaust gas driven air pumps that can be used on gas and diesel engines - air is compressed and sent to cylinders - wastegate valve - air compresses around 2000 engine RPM - need recommended oil, and need engine to idle before shutdown.
What are the characteristics of OBD 1 system?
- First usde in 1980's - Diagnosed engine controls and sensors - Differed across manufacturers - Notified driver of concerns with check engine lamp
What are the types of Fuel?
- Gaslone - Diesel - Biodiesel - E-85 - Methanol - Compressed Natural Gas (CNG) - Liquified Petroleum (LPG)
The continous fuel inejction system is used on what type of vehicles?
- Imported vehicles - Racing Vehicles
What are the three types of sensor used in the Air induction system?
- Intake Air Temperature (IAT) sensor - Mass Air FLow (MAF) sensor - Manifold Absolute Pressure (MAP) sensor
What are the characteristics of the Mechanical Continous Fuel Injection SYstem?
- Known as constant flow systems - Used in racing vehicles
When does the engine produce maximum and least amount of vacuum?
- MAX: At idle - MIN: engine load or wide open throttle
What are the characteristics of OBD 2 system?
- Mandated in 1996 - Standardized OBD systems across manufacturers - Warns driver of concerns with Malfunction Indicator Light (MIL) - Identifies concerns with diagnostic trouble codes (DTC's) - Monitors multiple sensors such as; catalyst effeiciency, oxygen snesor aging, engine misfire, exhaust gas recirculation (EGR), secondary air injection system flow, evaporative emissions leaks, fuel adaptation
What are different Fuel Supply systems?
- Mechanical Fuel System - Gravity Fuel System - Vacuum Fuel System - Electrical Fuel System
What are the different mode of Operation of the OBD 2 system?
- Mode #1 Displays current data. - Mode #2 Powertrain freeze frame data - Mode #3 displays stored DTC's (ranked most sever first) - Mode #4 clears DTC's - Mode #5 Provides oxygen sensor test results - Mode #6 Moitored emssion component data or CAN vehicles - Mode #7 Lists pending DTC's - Mode #8 OBD activation test - Mode #9 Vehicle information, emissions control system data - Mode 0A stores DTC's until the repair is verified
What are the three types of Air induction systems?
- Naturally Aspirate Air Induction system - Turbocharger air induction system - Supercharger air induction system
What two types of Igntiion coils exist?
- Oil-filled ignition coil (not common anymore) - E-core ignition coil (most common)
The first letter of the DTC indicates the location of the fault. Which DTC letters are used for this first section and what do they represent?
- P: Powertrain DTC - B: Body DTC - C: Chassis DTC - U: Network DTC
What are the 4 types of air filters?
- Paper air Filters - Cotton Gauze Air Filter - Centrifugal Air Filter - Foam Filter
What are the characteristics of the Supercharger air induciton system?
- Positive displacement air pumps - driven by crankshaft via a belt - Horsepower and torque improves - has a bypass that can be electronically or vacuum controlled, it allows the supercharge to idle or boost the supercharger. Boost can reach about 12 PSI - Need own oil supply
What are the components of the fuel pressure regulator?
- Pressure Spring (applies downward force to create pressure) - Diaphragm (mocing membrane that divides the chambers) - Fuel Inlet (allows fuel to enter the regulator) - Return Port (returns fuel to the tank)
What are the characteristics of the Step-down transformer?
- Primary winding is more turns than secondary - voltage decresease when voltage is induced to secondary winding
What is the main purpose of the Barometric Pressure (B.A.R.O) sensor in regards to the ECM?
- Provides input with the atmopsheric pressure where the vehicle is operating - ECM uses this infromation to perform correction to the amount of fuel injected. At higher elevations, the air density decreases, resulting in less air entering the combustion chamber. Becuase of this decrease in air density, the engine needs less fuel to form a combustible mixture.
What is the purpose of the Throttle Position Sensor (TPS) in regards to the ECM?
- Provides the ECM with an input about the position or angle of the throttle plate. - ECM uses this information to determine if the driver's request is for more or less power. - Monitors the acceleration or changes in the sensor and rate of change. - May also be used in junction with the Manifold Absolute Pressure Sensor (MAP) to calculate engine load.
What is the main purpose of the Mass Air Flow (MAF) sensor in regards to the ECM?
- Provides the ECM with input about the amount of air and air mass entering the engine.
What fuctions does the ECM have for the Engine Coolant Temperature (ECT) sensor in regards to the drivability of the engine and vehicle?
- Read engine coolant temperature - Determine if engine coolant or engine is too hot or cold - When the engine is cold, the ECM will advance the ignition timing to provide better throttle responce and improve idle quality. - When the engine temperature is high, the ECM will retard ignition timing to reduce the possibility of detonation and overheating.
What is the main purpose of the Oxygen (O2) sensor in regards to the ECM?
- Reads oxygen presence in exhaust system to determine if engine is properly burning fuel and indicate so. - Aids in mixture correction and diagnosis in regards to the engine if the mixture is too lean or rich.
What are the four main functions fo the ECM?
- Receive inputs - Process Data - Store data - command action
What are the characteristics of the Naturally Aspirated Air indcution system?
- Relies on atmospheric pressure - Has low pressure at idle - reaches atmospheric pressure at wide open throttle
What are the characteristics of the Air-to water intercooler?
- Removes heat from compressed air leaving turbo or supercharger - increase air density - increases power
What tools can you used ot determine if ta C.M.P sensor is faulty?
- Scan Tool - DMM - Osciloscope
What tools do you use to determine if a C.K.P sensor is faulty?
- Scan Tool - DMM - Osciloscope
What are the characteristics of the Step-up transformer?
- Secondary winding has more turns than primary - voltage increase when voltage is induced to secondary winding.
What are the different types of on board diagnostic systems?
- Self-diagnostics - Service Light - Fault Code - Diagnostic Trouble Code (DTC)
What are the three injector operating sequences?
- Sequential (one cylinder after the other) - Batch or Non-sequential (small batches or rows fireing at the same time - simultaneous (all injecotrs fire, typically used for engine start up)
For an engine to start and run properly, what three things are necessary?
- Sufficient Compression - A timed spark - Fuel and air mixed in the correct ratio
What is the main purpose of the Knock Sensor in regards to the ECM?
- Supplies data to the ECM for correction of ignition timing - Determine the severity of engine knock and adjusts ignition timing to reduce or eliminate it.
What purpose does the Intake Air Tempeerature (IAT) sensor provide for the ECM?
- This sensor provides, temperature of the incoming air entering the induction system. - Used to change the air/fuel mixture becuase of air density changes with temperature. - Cooler air is denser and accepts more fuel. Warmer air is less dense and accepts less fuel to remain within stoichiometric range.
What are the different types of electronic fuel inejction?
- Throttle Body Injection (TBI) - Port Fuel Injection (PFI) - Gasoline direct injection (GDI)
What are the different code types of DTC's?
- Type A: emission related, MIL illuminates after first failed trip - Type B: emission-related, MIL illuminates after failing on two consecutive trips - Type C: Non-emission related, service engine soon lamp illuminates - Type D: Non-emission related, service soon lamp illuminates, include manufacturer specific systems
What are the characteristics of the Manifold Absolute Pressure (MAP) sensor?
- Used in fuel injectd engines - Used in an internal combustion engine's electronic control system - provides instantaneous manifold pressure information.
What are the characteristics of the KE-Jetronic Continous Fuel Injection System?
- Uses mechanical fuel injectors - includes an ECM, pcygen sensor and pressure actuator
What are the three types of fuel pressure regulators?
- Vacuum-modulated regulator (used on return fuel systems, holding constant pressure differential) - Atmospherically-modulated regulator (modifies fuel pressure with changes in atmospheric pressure) - Constant pressure regulator (returnless fuel system, pressure is determined by springs)
What are the Three most common types of M.A.F sensors?
- Vane Airflow Sensor - Hot WIre type sensor - Karman Vortex Sensor
Remember Ohms Law?
- Voltage = Amperage x Resistance - Resistance = Voltage / Amperage - Amperage Voltage / Resistance
What is run mode, and what are the different types?
- When the engine first starts and RPM is above 600. There is open loop and closed loop. - Open loop operation, the ECM ignores the signal from the O2 sensor and calcualtes the injector timing based on the ECT, MAP and MAF sensors. Once parameters for each of these sensors has been met, The system will then enter closed loop mode. - Closed loop operation, the ECM will include the singal from the O2 sensors. It will also adjust air/fuel ratio based on such data.
What are the characteristics of the Electronic distrubutorless ignition system?
- completely ECM-controlled - provides longer dwell and more pwoerful spark - reduce component maintenance - more reliable ignition - provide better control of emissions - use feedback from multiple engine sensors
What are the characteristics of the Electronic Distrubutorless ignition system?
- controlled entirely by the ECM and electronic components - uses the crankshaft position sensor data - uses either one coil per spark plug or one coil for multiple spark plugs
What are the characteristics of the Mass Air Flow (MAF) sensor?
- loacred in ductwork BEFORE throttle body assembly - relays infromation to engine contorl module - measured airflow ensures proper mix of air and fuel in cylinder
What are the characteristics of the Intake Air Temperature (IAT) sensor?
- located in or neat air cleaner assembly - relays temperature of incoming air to engine control module - uses ambient air temperature to adjust air to fuel ratio
What are the characteristics of the Electric Fuel Pump?
- located inside the fuel tank - used in newer fuel-injected vehicles - controlled by relay or module
What are the characteristics of the Breaker Point ignition system?
- mechanicall operated by camshaft rotation - breaker points open and close to provide voltage to the coil for mutual induction - distrubutor delivers high voltage to the spark plugs
What is the purpose of the Manifold Absolute Pressure (M.A.P) sensor in regards to the ECM?
- provides the ECM with input about the air pressure within the intake manifold. - ECM uses input data to determine engine load along with T.P.S and engine speed. At idle the manifold pressure is low. - AS throttle opens, the manifold pressure increases - Most common operating voltage is between 1 volt and 5 volts
What are the characteristics of the Air to Air intercooler?
- removes heat from compressed air - increases air density and mounts in the front of vehicle - recives air flow through grill opening
What are the characteristics of the Mechanical Fuel Pump?
- used in older vehicles - mount to the engine block - operate off an eccentric camshaft lobe
What are the characteristics of the Electronic distrubutor ignition system?
- uses a distributor witha sensor instead of points - controlled by the ECM
What is the typicaly voltage range for a T.P.S?
0.5 volts to 4.5 volts
Exhaust backpressure should not exceed how much PSI at wide-open throttle?
1.75 PSI
The Clean Air Act was passed when?
1963
From what years to what years were Single-point or Throttle Body Fuel injection systems used in Automotive vehicles?
1980 to 1995 saw a use of this style of fuel delivery system for passenger cars and light trucks
When was OBD 2 required?
1996
If a TPS sensor is open, what will the PI..D display?
5.00 volts will be shown at this sensor if open
An engine with WEAK VACUUM or LEAKS can often make this type of noise
A WHISTILING NOISE coming from the engine is a byproduct of?
What is Port Fuel Injection (PFI)?
A fuel delivery system that injects fuel at a central point within the intake port just ahead of each cylinder intake valve. IT also injects fuel at the same time to all cylinders.
During deceleration what mixture allows lower emissions?
A leaner fuel mixture reduces the emission of Hydrocarbons (HC) and carbon monoxide (CO).
What is sequential Fuel Injection (SQI)?
A mutliport-inject design that fires each injector independently in a specific firing order instead of all at once as in PFI or MFI systems. Each injector is indepedent and sprays fuel just before the intake valve opens.
What is acceleration enrichment mode?
A rapid change in MAP signal, supplies additional fuel for a short period. Any reduction in throttle angle cancels enrichement mode as to prevent over-enrich the mixture.
What is SOLVENT SPRAY TESTING?
A test involving running the engine and spraying the intake and manifold gasket areas and vacuum hoses with carburetor or choke cleaner. Listen for RPM change or for a rough idle to smooth out. You can also monitor the oxygen sensor using an oscilloscope or scna tool. Any increase in O2 sensor signal voltage while spraying carburetor cleaner, indicates a leak.
What is a cranking vacuum test?
A test performed to see how much vacuum and engine can produce when cranking. It is alos used to check for internal air leaks or incorrect valve timing. The minimum vacuum for this test is 3 inches or vacuum or mercury.
What can occur inside the intake manifold with a carburetor fuel delviery system?
Condensation, a build up of liquid fuel
What is C.A.N stand for in relation to the OBD system?
Controller Area Network
What is the purpose of the air induction system?
Direct, and move air into the engine suitable for combustion.
What is the main purpose of the Fuel Pressure Regulator in the Fuel System?
It is miunted at the end of the fuel rail and controls fuel pressure. It is also typically vacuum controlled, while other may rely on a calibrated spring to control fuel pressure.
If a TPS sensor is shorted to ground, what will the P.I.D display?
Less than 0.5 volts will be shown at this sensor if it is shorted to ground.
What is Short-Term Fuel Trim?
Measured the same way as LTFT however, STFT changes faster than LTFT does becuase it mirror the O2 sensor signal. Signal values are NOT stored in the memory
What is the airflow sensor for and what is unique about its aplication in regards to the type of fuel delivery system it is paired with?
Measures the amount of airflow entering the engine. Commonly used in PFI but not in TBI.
What is Clear Flood Mode?
One some vehicles, if a flood condition exists the Driver must depress and hold the acceleration pedal wide open. The ECM either commands no fuel injection or changes the inejctor pulse rate to achieve an approximate air-fuel ratio of 20:1. The ECM holds this injector rate as long as the throttle plate remains in excess of 80% and the engine RPM is below 600. If the throttle position changes to less than 80%, the ECM returns to issuing injector pulses.
When in spark delivered into the combustion chamber in relation to the timing stage of the engine cycles?
Spark is delivered to the correct spark plug at a specified point before top dead center (TDC). This is called ignition timing.
What is Long-Term Fuel Trim?
The ECM's ability to correct fuel mixture problems due to various faults. Signal values are stored in the memory
What is the OBD system?
The On Board Diagnostic system, alerting the driver of system faults and stores trouble codes to identify concerns
The Sequential Fuel Injection (SQI) system relies on these sensors to operate correctly
The crankshaft position sensor and the camshaft position sensor aid to ensure fuel delivery happens just before the intake valve opens in this fuel delivery system.
What is the heat range of a spark plug?
The spark plugs ability to trasnfer heat away from the cetber electrode - length of the insulator determibes the heat range: - cold plugs have shorter paths - Hot plugs have longer paths
Where is a fuel pressure regulator in a returnless fuel system?
This component is located in the fuel tank in a returnless fuel system
What is a VENTRI?
This is a restriction designed to create a pressure differential
What is a SMOKE TEST?
This type of test involves using a machine to push pressurized smoke into the intake manifold. Visible smoke seeping out around the intake areas indicates a leak.
What is the purpose of the fuel rail?
To deliver fuel to all fuel injectors from a common source.
Most temperature sensors in a vehicle are of what type of thermistor?
Typically a negative temperature coefficient thermistor, they are classified as "NTC". In these sensors as temperature increases, resistance decreases. Voltage will also decrease as resistance decreases.
What is PRESSURE TESTING?
Using a device to pressurize the intake manifold, allowing you to listen for seeping air. It uses a pressure regulator to limit the air pressure to safe levels. This test also can be used with soapy water to look for bubbles that may also indicate leaks.
What is Multiport Fuel Injection (MFI)?
Virtually the same as PFI, but the fuel injectors fire in groups rather than all at the same time. With the groups split into banks, each bamk fires alternately per revolution.
This type of fuel delivery system was used on older vehicles and used low air pressure to be delivered into the intake manifold
What is the Carbureator fuel delivery system?
If an ECT sensor circuit is OPEN what value will the PID display?
With this condition the PID will display -40 degreese farenheight.
If an ECT sensor circuit is shorted to ground what will the PID display?
With this condition, the PID will display 120 degreese celsius or 248 degrees farenheight.
If there is compression loss but there is no leak, what is the most common or likely cause?
Worn camshaft lobes that do not open the valves far enough or incorrect valve timing.
Will most modern vehicles incorporate the IAT into the MAF sensor?
YES
Can the crankshaft position sensor detect when the piston in cylinder 1 is at TDC?
Yes, but it cannot identify which stroke it is on. Adding the cam shaft position sensor allows the ECM to identify the intake stroke, which is necessary for sequential injector firing.
When were most returnless fuel system used?
mid 1990s this fuel system became popular.
What are some various METHODS OF VACUUM LEAK TESTING?
these different types can be used for a general type of test to indicate a(n) change in aerodynamic force in the engine. - SMOKE TESTING - PRESSURE TESTING - SOLVENT SPRAY TESTING
Over time the ENGINE WEARS DOWN and loses this type of aerodynamic force.
what can VACUUM LOSS be caused by?
