The Mass Air Flow (MAF) sensor, equipped on the 3.1L engine only, measures the amount of air which passes through it. The PCM uses this information to determine the operating condition of the engine to control fuel delivery. A large quantity of air indicates acceleration, while a small quantity indicates deceleration or idle. The volume of air is measured in grams per second.
If there is a failure on the MAF sensor circuit, A Diagnostic Trouble Code (DTC) will set. Refer to Trouble Codes in this section. The only test that can be done with a DMM is to check that the sensor is supplied with a 5 volt reference signal, as follows:
- Disconnect the MAF sensor electrical connector.
- Turn the ignition ON (engine should be OFF ).
- Set the DMM to the DC volts scale.
- Attach the negative probe of the DMM to a good ground or the negative battery terminal.
- Carefully probe the C terminal with the red lead of the DMM.
- The DMM should read battery voltage. If the PCM is not sending the correct voltage, the problem is with the PCM or the wiring harness.
REMOVAL & INSTALLATION
- Detach the MAF sensor electrical connector.
- Loosen the clamps on both sides of the MAF sensor.
- Remove the MAF sensor.
- Position the MAF sensor into the intake duct and air cleaner outlet.
- Tighten clamps on both sides on MAF sensor.
- Attach the MAF sensor electrical connector.