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Anyone have any thoughts what might be wrong?

J

JuilinSandar

New member
Car check engine light came on a few days ago and car started sputtering and stalling while parked or driving. Got diagnostics checked and got code P0102. Changed the MAF sensor and it helped for a day then it started again and now the lights flicker and the car stalls while driving and parked. Got the wiring checked on the MAF and thats all good. Replaced the MAP sensor and still nothing and now my car's speedometer is reading wrong while driving. Checked the fuses and there fine...I am really at a loss. I am starting to think its the main computer seeing as all sensors seem to be having problems including speed (cause of speedometer I assume). While the car was under diagnostics it seemed to read all normal and then all the sudden all the gauges would go crazy then normal again and just seemed to go back and forth and stall out. Any suggestions? 2003 Grand Prix FYI.
 


Crank position sensor.

That's my guess.

The one sensor that can possess your car and show know signs of failure. Lol
 
Some things to check: PCM connection, Power/Grounds, Ignition switch.........

When hooked up to scan equipment, your are seeing what the PCM is receiving via sensor output. Many of the sensors utilize a 5 volt reference and the voltage variation is interpreted by the PCM and that data is what you see on the scan data display. Proper power and ground are essential and if there is a connector fault any data received by the PCM will be flawed. An old rule of thumb when dealing with vehicle diagnostics...GARBAGE IN-GARBAGE OUT. If the PCM is functioning properly,it is only as good as the data it receives.
 
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So its looking like its the PCM. Mechanic can't find anything wrong just keeps wrong bad then good and all sensors seem to be fine. Anyone know how much to replace the PCM should cost or if its and easy install to do your self?
 
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