21.   Technician A says the PCM will advance ignition timing when it receives a voltage signal from the knock sensor. Technician B says this sensor sends an AC signal to the PCM when it detects ping or spark knock. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

26.  A vehicle cranks slowly but will not start. As the technician turns the ignition key the security light continues to flash slowly. Which of these is most likely the cause?

A. The ignition switch.

B. A faulty PCM.

C. No power to to the injectors.

D. A dead battery.

22.   There is a misfire at the #3 cylinder of a COP ignition system. There is no power at the Bat+ terminal of the coil. Which of these is most-likely the cause?

A. Resistance in the primary circuit.

B. Resistance in the secondary circuit.

C. A leak in the secondary insulation.

D. An open between the coil and the PCM.

27.   A vehicle is backfiring and has a lack of power. Technician A says it may be the catalytic converter and a back pressure test should be performed first. Technician B says a vacuum gauge can also be used to diagnose a catalytic converter. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

23.   An enhanced EVAP system has a code indicating a gross leak detected. Which of the following is most likely the cause?

A. A crimp in the vent hose.

B. A saturated canister.

C. A stuck closed purge valve.

D. A loose fuel filler cap.

28.   Two technicians are discussing code P0171. Technician A says the P in the code stands for powertrain. Technician B says the 0 in the code means it is manufacturer specific. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

24.   A catalytic converter is damaged from heat. Technician A says this damage is most likely caused by cylinder misfiring. Technician B says this is most likely caused by low fuel volume. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

29.   Technician A says when the vacuum hose is disconnected from a vacuum operated fuel pressure regulator the fuel pressure should increase. Technician B says a restricted fuel return line can cause a vehicle to run lean. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B

25.  A vehicle has a fuel trim of +5 at idle and +25 at cruise. The vehicle has a steady oxygen sensor reading of 800Mv. When the vacuum hose is disconnected from the brake booster check valve there is no change in the oxygen sensors reading. The most likely cause for this reading is:

A. An intake manifold leak.

B. A faulty throttle position sensor.

C. A faulty oxygen sensor.

D. A kink in the fuel return line.

30.   Technician A says the camshaft position sensor signals the PCM when the camshaft is at TDC on the compression stroke. Technician B says on any pick-up coil type sensors the distance between the sensor and the ring is critical. Who is correct?

A. Technician A

B. Technician B

C. Both Technician A and B

D. Neither Technician A or B