The MAF, or Mass Air Flow sensor, is a critical component of the powertrain control systems of 1992+ panthers. Measuring the airflow into the engine, the PCM uses this sensor input for air/fuel ratio control and even transmission operation.
Issues with the MAF, including dirty sensor elements, can cause numerous driveability and performance issues which are difficult to diagnose.
Below you will find some information on electrically testing the MAF sensor for proper operation, courtesy enslow.
The following article was authored by enslow
, and was originally posted in this thread
A lot of people are complaining about poor drivability and fuel economy issues. While the MAF might be suspect, confirming it is the culprit, and confirming that the condition has been properly fixed had never been well addressed other than to clean it and describe better drivability. In some cases, as in mine, I fixed the drivability issue, but still failed AirCare. A number of people here have cleaned their MAFs and are still experiencing drivability issues, but assume the MAF is no longer the problem. This is not always the case!
I have cleaned my MAF before and still had a high MAF voltage. It took several cleanings to get it down. I wouldn't have known without measuring the voltage.
Symptoms include: Lack of power, spark knock, buck/jerk, hesitation/surge on acceleration, MIL DTCs P0171, P0172, P0174, P0175.
Testing procedure: MAF voltages (4-wire type)
- Start car and bring to operating temperature. Turn all accessories off, block wheels.
- Remove cover on back of MAF connector harness.
See 1st picture, "MAF Location"
- Insert pins into the back of the harness to contact the ground (black wire) and the MAF signal wire.
See 2nd picture, "Pins Installed"
- Connect voltmeter to measure voltage.
- Either take voltmeter with you into the drivers seat (you will need long wires) or have a second person in the car shift into drive.
- Measure voltage.
See 3rd picture, "MAF signal voltage"
- V = 0.6-0.75V: MAF is good. Look for other reasons for symptoms.
- V > 0.75V: MAF contaminated or faulty. Try cleaning according to the instructions given in the BOK.
- If voltage remains high even after cleaning, you may need to replace the MAF. You could try a more aggressive solvent at your own risk. But if you are faced with buying a new MAF anyway, that risk may be agreeable.
- The MAFs found on 1992-1994 models use a smaller 4 terminal connector shell versus the similar looking 6 terminal shell of 1995-2004 (exc. '04 CVPI) models.
- 2003-2004 models (exc. '04 CVPI) use the same connector type as '95-'04, but with two additional wires in the outer pin positions. These are for the IAT sensor
- 2004+ CVPI/2005+ retail MAF sensor and 1995-2004 MAF sensor pinouts;