Car has been up on jack stands for a couple months while I've been replacing the brakes and waiting for rims to be powder coated. Buttoned it all up yesterday and my CEL came on. Took it to Autozone and they pulled a P0603 - ICM KAM malfunction. Tested the battery and it was only at 65% charge. We assumed that was the reason the CEL came on and assumed it would go away on its own once the battery was charged back up. Ran to O'Reilly to have it scanned again at lunch and same thing - P0603. Dude asked if I wanted to reset it and told him to go ahead. It cleared the CEL, but now my display on the new Pioneer AVH-200EX won't come on. HU works fine in all other aspects.

Any clues to what happened here?

Found another instance of someone getting that code and resetting it.
https://g35driver.com/forums/audio-v...all-stuck.html

 

That's a pretty generic code for all vehicles I believe. Did you have the battery disconnected when the car was sitting?
Just keep driving it and see if the code comes back. The HU issue could just be bad timing. Make sure it has a good ground

 

Yep, battery was disconnected most of the time while everything was torn down. I'll get a closer look at the head unit after work and see what I can find out.

 

There's a pin hole on the front left corner. Used a paper clip to soft reset it and display is back. So CEL has stayed off and the display is back now. Let's see if they hold up.