Diag FAGG cards
Which is NOT a purpose or function of the MAP sensor?
Helps diagnose the EGR system.
A fuel injection system that does not use a sensor to measure the amount (or mass) of air entering the engine is usually called a ___ type of system?
Hot wire
The sensor that measures the temperature of the air being drawn into the engine is called which of these?
IAT
Where is sensor 1, bank 1 located on a V-type engine?
In the exhaust manifold, on the same bank where number 1 cylinder is located. Both a and B.
As the load on the engine increases, the manifold vacuum decreases and the manifold absolute pressure
Increases
What happens to the voltage measures at the ECT sensor when the thermostat opens?
Increases slightly
The primary purpose of the fuel trim is to keep the air fuel mixture as close to ______ as possible
Lambda and 14.7:1
The the below illustration what type of circuit is depicted?
Negative temperature coefficient (NTC) thermistor
This DVOM reading indicates a temperature of ___ for a GM ECT sensor
Neither A nor B
The sensor that must be warmed and functioning before the engine management computer will go to closed loop is the
O2s
When testing the ECT sensor with the connector disconnected, the technician should select what position on the DMM (digital multimeter).
Ohms
A TP sensor is what type of sensor
Potentiometer
Which of the following is a three wire variable sensor?
Potentiometer
Fuel lines are constructed from ________.
Seamless steel tubing and Nylon plastic
A corroded connector at the ECT could cause
Stored DTC, Air fuel mixture too rich, poor fuel economy. All of these
All of the following are approved methods for diagnosing a ECT (engine coolant temperature) sensor except
Substituting a variable resistor
The output of a MAP sensor is reading 1.0 volt. What is the approximate engine vacuum in inches of mercury (HG)?
17-21
Most fuel filters are designed to remove particles larger than ________.
20 microns
The map sensor is used to check the operation of the ___ on OBD 2 vehicles
EGR system
B. With the vehicle in close loop, the following post converter HO2S scope pattern activity is seen. What does this indicate
A bad converter
G. With the vehicle in close loop, the following post converter HO2S scope pattern activity is seen. What does this indicate
A good converter
A low O2S voltage could be due to a _______
A lean exhaust and a defective spark plug wire.
A typical MAP sensor compares the vacuum in the intake manifold to ___.
A perfect vacuum
A high O2S voltage could be due to a ______
A rich exhaust and a defective spark plug wire.
When checking an ECT sensor with a scan tool, about what temperature should be displayed if the connector is removed from the sensor with the key on, engine off?
-40*F (-40*C)
With the TP sensor in the position shown, what voltage would be expected at the signal wire (C)?
0.5 volts
A conventional oxygen sensor heater uses about ____ amps
0.8 to 2.0
A wide band sensor is capable of detecting the air fuel mixture in the exhaust from ___ rich to ____ lean
10:1 to 23:1
An IAT is being tested. After the vehicle has been allowed to cool for several hours, a scan tool is used to observe the IAT sensor reading. When compared to the engine coolant temperature(ECT), the two temperatures should be within how many degrees F of eachother?
5
Which wire on a TP sensor should be back probed to check the voltage signal to the PCM?
5 volt reference (Vref)
A conventional oxygen sensor heater keeps the sensor at about _____ degrees F
600
The first fuel filter in the sock inside the fuel tank normally filters particles larger than
70 to 100 microns
A typical IAT or ECT sensor reads about 3000 ohms when tested using a DMM. This resistance represents a temperature of about ...
70*F (20*C)
How long does the electric fuel pump run if the ignition is turned on but the engine is not started?
About 2 seconds
The component shown has a crack or spilt in it. What would this cause?
Allow false air into engine.
The wiring to the IAT sensor has high resistance (cut wire). What could this cause?
Black exhaust smoke, poor fuel economy, both are correct
Technician A says that the ECT and IAT sensors can be tested visually, as well as by using a digital multimeter or a scan tool. Technician B says that the ECT sensor is a high authority sensor at engine startup and is used for open loop control, as well as idle speed. Which technician is correct?
Both technicians
Technician A says the MAP sensors use 5-volt reference voltage from the PCM. Technician B says the MAP sensor voltage will be higher at idle at high altitudes compared to when the engine is operating at near sea level. Which technician is correct?
Both technicians
Technician a says that the ECT and iat sensors can be tested visually, as well as by using a digital multimeter or a scan tool. Technician b says that the ECT sensor is a high authority sensor at engine start up and is used for open loop control, as well as idle speed. Which technician is correct?
Both technicians
Technician a says the purpose of the intake Air temperature (IAT) sensor is to provide the engine computer (PCM) with the temperature of the air entering the engine. Technician B says that the IAT sensor information is used for fuel control ( adding or subtracting fuel) and spark timing. Depending on temperature of incoming air. Which technician is correct?
Both technicians are correct
When testing an ECT sensor on a vehicle, a digital multimeter can be used and the signal wire back probed. What setting should the technician use to test the sensor?
DC volts
If the transmission fluid temperature (TFT) sensor indicates cold automatic transmission fluid temperature, what would the PCM do to shifts?
Delayed shift points and torque converter clutch disabled.
The sensor that most determines fuel delivery when a fuel injected engine is first started is the
ECT sensor
Which of the following components provides the engine control computer with engine coolant temperature information?
ECT sensor
Technician A says that all other temperature sensors that operate like the ECT include the transmission fluid temperature(tft), and cylinder head temperature sensor. Technician B says that all temperature sensors increase in resistance as the temperature decreases. Which technician is correct?
Technician A
A DTC P0117 DTC is being discussed. Technician A says that the ECT sensor could be internally shortened to ground. Technician B says that the signal wire could be open. Which technician is correct?
Technician A only
Technician A says that an oxygen sensor produces a voltage output signal based on the oxygen content of the exhaust stream. Technician B says that if the exhaust has little oxygen the voltage of the oxygen sensor will be close to 0 volts. Which technician is correct?
Technician A only
A DTC P0113 is being discussed. Technician A says that the IAT sensor could be internally (electrically) shortened to ground. Technician B says that the PCM could be defective. Which technician is correct?
Technician B
A P0118 is being discussed. Technician A says that the ECT sensor could be shortened internally. Technician B says the signal wire could be open. Which technician is correct?
Technician B
Technician A says that all temperature sensors are PTC devices that decrease in resistance as the temperature increases. Technician B says that some vehicle manufacturers use a stepped ECT circuit inside the PCM to broaden the accuracy of the sensor. Which technician is correct?
Technician B
Two technicians are discussing a stepped ECT circuit. Technician a says that the sensor used for a stepped circuit is different than one used in a non stepped circuit. Technician B says that a stepped ECT circuit uses different internal resistance inside the PCM. Which technician is correct?
Technician B
Two technicians are discussing the IAT sensor. Technician A says that the IAT sensor is more important to the operation of the engine (higher authority) than the ECT sensor. Technician B says that the PCM will add fuel if the IAT Indicates that the incoming air temperature is cold. Which technician is correct?
Technician B
