2003 Chevrolet Trailblazer Electrical problems

[kolonelkadat]

I have a 2003 Chevrolet Trailblazer. Every now and then the door locks will rapidly lock and unlock. the heated seat will change temperature. the windows will stutter up and down. Ive been all over the net and have been told a dozen different things. This is not a constant fault. Maybe 1 in 3 drives this error will occur.

I started today with the door panel button module. It does appear to have damage, but Id like a professional opinion.
Ive marked the spots I think are troublesome.
odd white powder
black areas under solder mask
broken? traces

Any repair tips would be greatly appreciated.

[nctnico]

This looks like water damage. You better fix the leak. Using conformal coating may also help but if water continues to leak onto the board it will only be a short term fix.

[Zucca]

Normally in a car before to touch anything you should read out the OBD codes... have you tried that?

[SeanB]

It drowned. You can repair it, and then give it a conformal coat to protect it from further damage, but you should also fix where it is getting water in. My bets are fia the window edge and through the door latch, along with it coming through inside when you drip on the door itself. Place some sheet plastic to cover the board from the top and sides, leaving the bottom open to allow drainage and the new one will last longer.

the black is corrosion of inside tracks and layers, and the white is from areas which are always 12V supplies that got wet.

[kolonelkadat]

Normally in a car before to touch anything you should read out the OBD codes... have you tried that?

I hadn't, because it passed emmisions testing and OBD codes result in automatic failure. But I just checked a few moments ago and it reported "no codes"

It drowned. You can repair it...
the black is corrosion of inside tracks and layers, and the white is from areas which are always 12V supplies that got wet.

I made a particularly sad attempt to remove the solder mask and corrosion. Then put some solder over the top of the bare copper in hopes of preventing further damage. I may have made a mistake in bodging a sot23 to a capacitor. But who knows.

I will leave it like this for now. I dont want to coat it or anything until I know i didnt mess anything up.
 

thanks for the input guys.