PCM?
How do you know when your PCM is bad? I lost power to ignition and cluster along with a few other things and was told by the mechanic that the PCM was bad and my options were a rebuild for $900 or a n...
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How did he diagnose it?
The only time I've seen that happen on a GM truck, the PCM was fine. But it kept blowing fuses. It turned out to be a short in one of the oxygen sensor harnesses, which melted from the hot exhaust (pass side). This O2 sensors and crank sensor were the only components on the same circuit as the PCM. I had to isolate and test each branch circuit until I narrowed it down.
The only time I've seen that happen on a GM truck, the PCM was fine. But it kept blowing fuses. It turned out to be a short in one of the oxygen sensor harnesses, which melted from the hot exhaust (pass side). This O2 sensors and crank sensor were the only components on the same circuit as the PCM. I had to isolate and test each branch circuit until I narrowed it down.
