BLOCK C: Vehicle Management Systems Flashcards
A vehicle has an illuminated MIL. A P0133 code (O2 sensor circuit slow response) is present. While monitoring the O2 sensor, what test procedure would verify a slow response time?
a. Create a lean condition, then clear the
codes and road test the vehicle.
b. Create a lean condition, then a rich condition, and monitor response time.
c. Ground the wire to the sensor, then monitor the scanner for low voltage.
d. Install a resistance in the signal wire at the O2 sensor, then watch for a response
b. Create a lean condition, then a rich condition, and monitor response time.
How many characters does an OBDii diagnostic code have?
a. 2.
b. 3.
c. 5.
d. 8.
c. 5
An exhaust manifold is cracked. What type of signal would an oxygen sensor feed the ECM?
a. Stoichiometric condition.
b. Rich fuel condition.
c. Lean fuel condition.
d. DTC
c. Lean fuel condition.
Which sensor should indicate a value close to Barometric pressure in a neutrally aspirated gasoline-fueled engine?
a. MAP sensor.
b. TP sensor.
c. ETC sensor.
d. TBS sensor.
a. MAP sensor.
A vehicle’s Malfunction Indicator Lamp has been illuminated for the past three days but has no drivability concerns. After installing a scan tool what diagnostic steps should be performed?
a. Check the data stream, then check for trouble codes.
b. Perform bidirectional tests, then check freeze frame data.
c. Check for trouble codes, then clear the codes from memory.
d. Check the freeze frame data, then check failure records.
d. Check the freeze frame data, then check failure records.
Refer to the chart below. A vehicle has an intermittent MIL. DTC P0118 (Engine Coolant Temperature Circuit High Input) is present. The information below is stored in freeze frame data. What procedure must be used to capture this fault?
ECT IAT MAF RPM HO2B1S1 HO2B2S1 VSS MAP LOOP
5.0V 2.3V 3.5V 1515 0.75V 0.75V 5mph 4.0V OPEN
TPS MIL DTCs
3.1V ON YES
a. Test the signal line to the sensor for high resistance, then clear the code and road test to complete the drive cycle.
b. Test the ignition power fuse for an intermittent open to the PCM, then perform the drive cycle.
c. Test the sensor ground terminal for an intermittent open at the PCM, then perform the drive cycle.
d. Test the connections in the coolant sensor circuit then install a meter on the signal line on glitch capture and complete the drive cycle
d. Test the connections in the coolant sensor circuit then install a meter on the signal line on glitch capture and complete the drive cycle
A MIL is illuminated. A scan reveals the DTCs noted in the chart are stored in the PCM memory, indicating an open at the PCM terminal for sensor ground. What test in the ground circuits will confirm this diagnosis?
P0108: MAP high input P0405: A/C charge low
P0113: IAT high input P0450: Fuel tank pressure
P0118: ECT high input P0713: TFT high input
a. Locate the grounds in the manual, then perform a voltage drop on the ground connections while the circuits are functioning.
b. Check for high resistance to ground with an ohmmeter, then remove and clean the grounds.
c. Clean the PCM terminal for sensor grounds, then clear the codes and road test.
d. Determine the ground locations in the manual, then test them with a test light while the circuits are functioning.
a. Locate the grounds in the manual, then perform a voltage drop on the ground connections while the circuits are functioning
After obtaining trouble codes from a vehicle, in what order is the diagnosis performed?
a. Record the codes and consult freeze frame data.
b. Clear the codes and then consult failure records.
c. Record the codes and consult failure records.
d. Clear codes and duplicate freeze frame on road test.
a. Record the codes and consult freeze frame data.
A vehicle is hard starting and surges intermittently during acceleration. The data captured in a snap shot with the scan tool suggests an intermittent open at the throttle position sensor. How would a technician diagnose this problem?
a. Read the drive cycle section in the manual, then road test to duplicate the problem.
b. Read the enable criteria section for the code, then replace the TPS sensor.
c. Consult the symptom charts, then follow the diagnostic aids in the manual.
d. Consult the trouble code chart, and then replace the component.
c. Consult the symptom charts, then follow the diagnostic aids in the manual
Refer to the chart below. The torque converter on the vehicle will not engage. The listed data was recorded while driving on the highway. Which defective component is causing the problem? ECT Brake Switch TPS RPM TR SS1 SS2 VSS 0.6V ON 2.2V 3175 3 ON ON 50mph TCC MIL DTCs 0% OFF NO a. Vehicle speed sensor b. Brake switch c. Thermostat d. Transmission range switch.
b. Brake switch.
A vehicle has had an illuminated MIL for the past three days, but has no drivability concerns. DTC P0135 (O2 sensor heater circuit problem, bank 1, sensor 1). What causes the code to set?
a. A poor voltage supply for the oxygen sensor heater at the PCM
b. Blown fuse for the ignition feed to the PCM
c. A bad connection at the ground terminal of the O2 sensor heater circuit
d. A short at the power feed terminal at the oxygen sensor heater circuit.
c. A bad connection at the ground terminal of the oxygen sensor heater circuit.
A tech is diagnosing a vehicle with a no-start complaint. An injector pulse is observed with an injector test light, but there is no spark at any ignition coil. What component has likely failed?
a. Mass air flow sensor
b. Crankshaft position sensor
c. Throttle position sensor
d. Ignition control module.
d. Ignition control module.
An O2 sensor is giving a continuous reading of 0.2 volts. What is causing this reading?
a. A leaking fuel injector
b. An open winding in an injector
c. A plugged catalytic converter
d. A vacuum leak to the MAP sensor hose
b. An open winding in an injector
Before replacing a control module, all outputs are checked for shorts and grounds. What else should be tested?
a. Module programming chips
b. Pinpoint tests on inputs
c. All module powers and grounds
d. Pinpoint tests on all outputs
c. All module powers and grounds.
A coolant sensor code is stored. A DVOM shows 0.0V on the coolant temperature sensor sense line circuit. A faulty connection or an open in the sense line could cause this. How should this be tested?
a. Measure voltage drop on the sensor circuit, then monitor the scan tool for changing temperature.
b. Disconnect the sensor, then test the resistance of the sensor and compare to the service chart.
c. Disconnect the sensor, jump the terminals, then watch the scan tool for a high temperature reading.
d. Measure the sense line for an open circuit with a voltmeter, then replace the sensor.
c. Disconnect the sensor, jump the terminals, then watch the scan tool for a high temperature reading
A computer network has stopped communicating. The technician has located and disconnected the splice pack. What procedures should be followed next?
a. Test the resistance in the wire, then test for voltage present.
b. Test the circuit for continuity to ground, then test for short to power.
c. Test the circuit for shorts, then check for grounds on the power line.
d. Test the circuit for power with a test light, then test for grounds.
b. Test the circuit for continuity to ground, then test for short to power.
An A/C signal generator is being tested for an output signal. Which characteristics would indicate a good signal?
a. The peaks should be even all the way across the wave form and they should be the same height both positive and negative.
b. The peaks should be irregular across the wave form and they should be the same height both positive and negative.
c. The pattern should be a saw tooth shape and repeat itself.
d. The pattern should be bell shaped and go in opposite amplitude as it is being tested.
a. The peaks should be even all the way across the wave form and they should be the same height both positive and negative
What engine operating condition must be met before a bidirectional scan tool can perform a cylinder balance test and what does the scanner actually do?
a. Engine at operating temperature; turns off individual injectors.
b. Engine at operating temperature; turns off individual ignition coils.
c. Engine at cold start temperature; turns off individual injectors.
d. Engine at cold start temperature; turns off individual ignition coils.
a. Engine at operating temperature; turns off individual ignition coils.
In a typical DIS ( distributorless ignition system) described as a waste spark system, Which of the following should be true?
a. 2 spark plug per cylinder.
b. 2 ignition coil per cylinder.
c. 1 coil for every 2 spark plugs.
d. A single ignition coil is used.
c. 1 coil for every 2 spark plugs.
When testing an ignition coil with a 3-light logic probe, what is indicated when the yellow light is indicated?
a. Voltage exceeds 10V.
b. Voltage exceeds 4V.
c. Voltage is 0V.
d. Voltage is changing.
d. Voltage is changing.
When a knock sensor signals a detonation condition, What does the ECM do to rectify the condition?
a. Inject less fuel.
b. Inject more fuel.
c. Retard ignition timing.
d. Advance ignition timing.
c. Retard ignition timing.
What would remedy a complaint that a spark plug was running hot?
a. Plug with a longer ceramic insulator.
b. Plug with a shorter ceramic insulator.
c. Plug with shorter protrusion into the
cylinder head.
d. Plug with longer protrusion into the
cylinder head
b. Plug with a shorter ceramic insulator.
What is the length of time the ignition module allows current to flow through the primary winding known as?
a. Dwell.
b. Coil saturation.
c. Base timing.
d. Inductive kick
a. Dwell
Which of the following actions would remove data logged into a NV-RAM (non-volatile random access memory) chip?
a. Cycling the ignition switch.
b. Turning the engine off.
c. Disconnecting the MAF sensor.
d. Disconnecting the battery.
d. Disconnecting the battery.
When a NTC (negative temperature coefficient) ECT ( engine coolant temperature ) sensor is subjected to heat, what happens to its internal resistance?
a. Remains unchanged.
b. Increases.
c. Decreases.
d. Dead shorts.
c. Decreases.
negative temperature coefficient
When replacing an ECM, what safety steps should be taken to prevent any damage to the computer?
a. Wear a static strap and place a rubber mat on the seat.
b. Disconnect the battery, and then remove the computer.
c. Remove the electrical connections, and then remove the computer.
d. Spray anti-static compound on the seat and then wear a static strap.
a. Wear a static strap and place a rubber mat on the seat.
What is the correct process for repairing broken computer wiring?
a. Replace the wire in the harness, then install and solder new terminals at the computer.
b. Strip and connect the wires, then twist and tape them before soldering the connection.
c. Secure the wires by twisting and ten use a heat sink when soldering the wire.
d. Replace the complete harness, then secure the terminals at the computer with solder.
c. Secure the wires by twisting and then use a heat sink when soldering the wire.
What is the correct process for repairing broken computer wiring?
a. Replace the wire in the harness, then install and solder new terminals at the computer.
b. Strip and connect the wires, then twist and tape them before soldering the connection.
c. Secure the wires by twisting and ten use a heat sink when soldering the wire.
d. Replace the complete harness, then secure the terminals at the computer with solder.
c. Secure the wires by twisting and then use a heat sink when soldering the wire.
