Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
P0480 cooling fan relay 1. Low speed won't work. The free wire commands low speed when grounded from pcm, this is not happening. I replaced the engine. Now I have this problem, so I am verifying all my grounds are connected. It didn't do this before, so hopefully something I over looked
Pin 42 on pcm is broken off from corrosion.
Good to hear you found problem. Let me know if you have more questions, thanks!