8B Quiz 18

Technician A recommends testing the battery before reprogramming the electronic controlmodule (ECM). Technician B recommends disabling the daytime running lamps whilereprogramming. Who is correct?

• Tech A

• Tech B

• Both

• Neither

Technician A says that a fault in the ground circuit of one of the pictured coils will cause amiss on one cylinder. Technician B says that an open in the power wire will cause the vehicle not to start. Who is correct?

• Tech A

• Tech B

• Both

• Neither

A vehicle that failed the I/M test for excessive NOx emissions will likely have to be tested under what vehicle condition to duplicate the concern?

• Idle

• Heavy acceleration

• Light acceleration

• Deceleration

A poor-quality air filter has been installed in a vehicle, and the MAF sensor is now contaminated. Which code will this condition most likely set?

• P0174–system rich

• P0171–system lean

• P0101–MAF sensor performance

• P0131–O2sensor low voltage

A long-term fuel trim of 20 percent is indicated on the scan tool. Technician A says that this indicates a rich condition. Technician B says that this could be the result of excessive fuel pressure caused by an unapproved aftermarket fuel pressure regulator. Who is correct?

• Tech A

• Tech B

• Both

• Neither

A cracked spark plug will be displayed on the secondary voltage pattern as:

• A higher firing line

• A lower firing line

• A shorter dwell period

• A longer dwell period

To test the operation of an O2sensor, a vacuum line is removed. The voltage of the sensor should:

• Decrease

• Increase

• Fluctuate rapidly

• Show no change

A low voltage condition displayed by the O2sensor will LEAST LIKELY be caused by:

• Low fuel pressure

• A vacuum leak

• The EVAP purge valve stuck open

• A cylinder misfire

The results of a cracked exhaust manifold would be:

• Higher engine RPM

• Higher O2sensor voltage

• Lower O2sensor voltage

• Lower engine RPM

Technician A says that when CO levels are high the technician will have to diagnose a lean condition. Technician B says that when O2levels are high the technician will have to diagnose a rich condition. Who is correct?

• Tech A

• Tech B

• Both

• Neither