A1 through a8 plus L1 package deal.
A-8 Engine Performance Certification Practice Test Answers
1.

Answer A is wrong. When a manual vacuum pump is used to activate the EGR valve the solenoid is being bypassed..

Answer B is wrong. A vacuum source of 18Hg is will activate the pintle.

Answer C is correct. A restriction in one of the EGR passages is common and should be cleaned out before replacing the EGR valve. It's carbon, use a small wire brush to clean out the passage.

Answer D is wrong. The EGR position sensor is used to inform the ECM of the position of the EGR pintle.

Return    Learn more about exhaust gas recirculating EGR systems.
2.

Answer A is wrong. Both technicians are correct.

Answer B is wrong. Both technicians are correct.

Answer C is correct. Both restricted fuel injectors and leaking secondary wires will reduce the cylinders contribution. This could happen. It is also likely the head gasket is at fault.

Answer D is wrong. Both technicians are correct.

Return    Learn more about cylinder power balance testing.
3.

Answer A is wrong. A faulty PCM driver will cause no spark at only one coil.

Answer B is wrong. Resistance in the primary circuit will cause no spark at only one of the coils.

Answer C is wrong. Resistance in the secondary circuit will cause no spark at only one of the coils.

Answer D is correct. No power to or a faulty PCM will result in no power to any of the coils and a no spark condition. With a coil on plug COP system, a faulty crankshaft position sensor can also cause a no spark condition for all of the cylinders.

Return    Learn more about coil on plug COP ignition systems.
4.

Answer A is wrong. A Manifold Absolute Pressure Sensor or MAP sensor senses the pressure in the intake manifold indicating engine load.

Answer B is correct. The Mass Air Flow Sensor or MAF sensor senses air volume in the air tube to indicate engine load. These are two different sensors used to inform the ECM of engine load. They will effect an engines fuel trim.

Answer C is wrong. Technician B is correct.

Answer D is wrong. Technician B is correct.

Return    Learn more about the MAF mass air flow sensor.
5.

Answer A is wrong. The TPI, TPS, or throttle position sensor is a potentiometer that varies voltage signals to the ECM. Both Technicians are correct.

Answer B is wrong. This sensor is best tested with a scanner but can be tested with a ohmmeter as well. Both Technicians are correct.

Answer C is correct. Both Technicians are correct.

Answer D is wrong. Both Technicians are correct.

Return    Learn more about the TPS throttle position sensor.