PCM Problems HELP
Thread Starter
Teching In
Joined: Nov 2014
Posts: 15
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PCM Problems HELP I have a 1999 blazer with 5.3 swap and when I unplug my pcm and plug it back in it does fine until I turn it off . When I try to start it back the security light comes on, the fuel gauge, the temp gauge, and gear selection indicator doesn't work but the engine starts and runs fine. I unplug the pcm then plug it back in everything works fine till I turn it off. I've tried two pcm's same results. When its working my obd scanner will connect to the pcm when its not it won't connect. Any ideas?
You have a loose or shorted wire, it is making the Class-2 bus to fail. The OBD2 plug and the cluster are both hooked to that bus.
If you can't find the damaged wire you may want to run a new one directly from the PCM to the cluster and OBD2
If you can't find the damaged wire you may want to run a new one directly from the PCM to the cluster and OBD2
