Mechanics

PONTIAC GRAND PRIX SENSOR PROBLEM

2002 Pontiac Grand Prix • 160 miles

I am having issues with the ECM. I keep getting a low mass air flow reading (zero reading). I found that there was something wrong with the oxygen sensors that were shorting the mass air flow input to 4 ohms impedance on the output. After disconnecting the oxygen sensors the impedance was back to a high value which is what I would expect from a digital input. After connecting a different mass sensor, I still get the same reading. Is there a schematic diagram available for the ECM? I think there is an open inside the ECM module. Any other thoughts?
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Guest
February 14, 2013.




If you are right about the o2 dragging down the mass air flow, then there is nothing wrong with the mass air flow. Replacing the sensor will do nothing.
There is no internal wiring diagram for the pcm.

Are there any codes? What are they? Lets start there

Roy

ASEMaster6371
Feb 14, 2013.


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