PCM SENSORS

The purpose of the CMP is to identify when number one cylinder is coming up on the ________ stroke.

• compression

• power

• intake

• exhaust

Answer explanation

Fun Fact: Engines with overhead camshaft design use multiple CMP to determine position of each camshaft. This is crucial for Variable Valve Timing operation.

If a high pressure fuel pump fails, which components supplies pressure to the injectors?

• fuel tank

• low pressure fuel pump

• high pressure fuel pump

• fuel regulator

what does the ignition switch supply power to first?

• cooling fan

• PCM / ECM

• Electric power steering

• blower motor

If an engine over temperature condition is determined by the PCM, the A/C compressor is turned on and set to maximum. True or False?

• true

• false

The electrical resistance of a thermistor ________ as temperature increases.

• stays the same

• increases

• decreases

• increases to the maximum

What downstream oxygen sensor voltage signal does a lean air fuel ratio produce?

• < 0.4 volts

• >0.60 volts

This sensor monitors and measures the temperature of the engine coolant.

• IAT

• ECT

• MAF

• IAC

Answer explanation

The Engine Coolant Temp sensor is generally located in an area of engine coolant (wet sensor). It is only accurate in reporting temperature when covered in liquid coolant.

The ______ is located in the cylinder head for measuring the temperature of the metal.

• HO2S

• ECT

• CHT

• IAT

Answer explanation

The Cylinder Head Temp sensor is usually a dry sensor (not in liquid coolant), measuring the temp of the metal (aluminum or cast iron cylinder head). The PCM uses its input to calculate engine temp.

A PCM/ECM input is usually an actuator or solenoid. True or false?

• True

• False

Which of the following is a tuned accelerometer on the engine which converts engine vibration to an electrical signal?

• IAC

• KS

• TPS

• CHT

Answer explanation

The Knock Sensor is a tuned accelerometer on the engine which converts engine vibration to an electrical signal. The PCM uses this signal to determine the presence of engine knock and to retard spark timing.