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C2500 MAF Sensor Low Voltage Code (P0102) - Diagnosis & Wiring Check Help

Model: MAF Fault Code: P2177 Posted: 2015-10-08 10:14

I own a 1999 Chevrolet C2500 with a persistent low voltage mass air flow (MAF) sensor fault code. The vehicle shows a P0102 code, indicating a low signal from the MAF sensor. I replaced the MAF sensor with a brand new unit and inspected all wiring for breaks or frays—no issues found. After clearing the code, the check engine light returned. When testing the sensor, I measured 5 volts on the pink wire (terminal C), while both yellow and black/white wires showed zero voltage. The truck consistently starts on the second attempt, which is concerning. I don't have access to a scan tool currently, so I'm relying on basic diagnostics. Any advice or troubleshooting steps would be greatly appreciated.

Related fault codes
P2177
Comments (4)
Anonymous 2015-10-08 13:45

What year is your truck? Is it P0102? You mentioned 5 Hz or 5 volts—could you clarify if it's 5 volts on the pink wire? Knowing the model year helps identify correct wiring colors and perform proper circuit checks. Do you have access to a scan tool?

Anonymous 2015-10-08 14:48

It's a 1999 model. I believe it was 5 volts on the pink wire. The yellow and black/white wires read zero. No scan tool is available right now—will head to AutoZone soon for testing.

Anonymous 2015-10-08 18:52

get a t pin available at walmart and hook neg meter to battery neg terminal and put t pin back probed in one at a time maf terminals and touch pos meter to maf terminal key on engine off.........terminal c pink wire should be close to battery voltage.........next back probe terminal a yellow wire should be 5 volts next back probe terminal b black/white wire should be less than .10 or 100 mv.let me know what readings you get.

Anonymous 2015-10-09 05:47

Thanks, Autojoe! I'll get a T-pin today and run the test—will update with my findings shortly.