1999 GMC Sonoma MISFIRE ON #2 CYLINDER

1999 GMC SONOMA

110,242 MILES • 4 CYL • 2WD • MANUAL

BISHOP6B

MEMBER
2 POSTS
FOLLOW

HELLO, I HAVE PULLED ERROR CODE P0200 OUT OF PCM ,STATES FUEL INJECTOR MALFUCTION. NOW I HAVE CONNECTED THE NOID TO ALL 4 INJECTOR HARNESS I GET A PULSATING LIGHT FOR #1-3-4 BUT #2 THE LIGHT STAYS ON CONSTANTLY SO THE PROBLEM ISN'T THE INJECTOR IS IT. I HAVE CHECKED THE HARNESS FOR SHORTS CAN'T FIND ANY? PLEASE HELP I DONT WANT TO CHANGE THE PCM YET IF THERES A WAY TO CHECK IT TO MAKE SURE. THANKS

Mar 30, 2008 at 2:11 PM

FLEXY5

CAR REPAIR CONTRIBUTOR
512 POSTS

One way to test it would be to disconnect the PCM harness at the PCM and perform an Ohm test for a short or for a ground problem on the wires for that injector. If there is no ground short and the resistance is ok, then it is the PCM. You could also just try tapping on the PCM to see if it will start working again. I have had a few times where that has worked. Try that and post back. If you have any other questions, feel free to ask.

Mar 30, 2008 at 6:05 PM

BISHOP6B

MEMBER
2 POSTS

thanks flexy5 performed those checks, it was the pcm (bad injector drive). i replaced it and the car is working perfectly!. thanks for the heads up.

Apr 11, 2008 at 4:49 PM

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