Ok, I have a 2010 gmc sierra crew cab with 5.3 and 56000m, just recently it started acting screwy. I'll just be driving down the road, and for no reason it will start going haywire. Haywire= lights flashing on and off, abs and stabilitrac lights flashing on dash, transmission going to neutral and motor reving, door dinger dinging, and doors locking and unlocking. It will last for a few seconds and then straighten back out, and only does it randomly. I have contacted onstar to see if anything is showing bad and nothing is coming up.

Any help would be appriciated since the electrical is out of warrenty.

The mods to the truck are vararam intake, flowmaster muffler and street tuned by Geoff Skinner.

 

Has anything been done to the truck recently that coincides with what it is doing? Have you messed with any of the grounds?

 

Replace the battery terminal ends. The factory ones short out and cause these trucks to go crazy with all the electronics.

 

Good point, I have seen that before.

 

Some of what you said is data controlled! So BCM? I would say it isn't "bad wires but rather a computer issue.

If it was me I would have a guy with a scanner check it. But as it isn't throwing codes and rather is BCM related I would swap out BCM and see.

Are the main battery wires fine? All the way with no shorts? They can internally short. Meaning check for wire resistance!

 

Nothing has been touched. The Ground does sound plausible as well as the BCM. But the ground seems easier and cheaper to replace. Ill check it out. Thanks for the ideas.

 

Just remember there are numerous grounds, these trucks are goofy when it comes to lose or bad grounds.

 

Do you know how to use or do you have a digital multimeter? If so super easy. Also I would unplug check and re plug the driverside fuse center. Never liked that design!

 

I have a friend who has one, Is there a ground wiring diagram anywhere?

 

Replace the battery cables there is a quick connect at the underhood UBEC that looses tension and is nine times out of ten where your exact problem arises. Check all the grounds on the block also