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93 k2500 suburban obd1 code 53 HELP

93 k2500 suburban 4x4 5.7l engine 4le80 trans no air con or power anything. with a obd1 code 53 (over voltage) i have checked the grounds to the pcm the voltage at the battery and pcm (14.4v) voltage at alternator (14.4v) and everything else related. after disconnecting the battery for 1 minute to clear the codes the code 53 still flashes before starting up the engine. i also have a very high idle(about 2200rpm) that i have not been able to cure that may be related.

is my pcm needing replacement.

Reply to
Nutpantz
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Is that 14.4 vdc at the battery while the engine IS or IS NOT running??

Reply to
hls

14.4vdc engine running 12.5 -13 vdc engine not running.
Reply to
Nutpantz

I'm no expert on this but I can commiserate with you. I double checked code 53 and found the following:

53 System voltage too high (over 17.7 volts to ECM) or EGR system fault or alternator voltage not normal or Vehicle Anti-Theft System fault

Your resting voltage is not high enough to set the 53 code. Doesnt mean that the ECM might not be faulty.

Your alternator voltage is normal.

I doubt the passkey II circuit is the problem. When I have had that sort of problem, the car just doesnt crank over. But keep it in mind.

EGR? Maybe related. If you cleared the codes, I am not sure how the EGR would create a fault code if you havent started the engine unless you have one of the electrical/electronically controlled EGR systems. GM started using them in some models in the late 80's or early 90's.

Maybe one of the guys here can give you some better pointers.

Reply to
hls

it was a bad pcm...

stupid computers..

nutz

Reply to
Nutpantz

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