Computer maybe (BCM)

2008 CHEVROLET SUBURBAN
155,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
Avatar
TAJ214
  • MEMBER
  • 1 POST
While driving down the highway my instrument cluster needles will go haywire and my door locks will start locking and unlocking on their own. my brake pedal will pulsate and my seat belt light will ding on and off. Sometimes my instrument clusters will just sit at zero even though I'm driving down the highway.
Feb 22, 2020 at 1:20 PM
Advertisement
Avatar
KASEKENNY
  • CERTIFIED EXPERT
  • 18,907 POSTS
This sounds like the voltage on the vehicle systems is too low. It is odd that this happens driving down the road but I have seen each of those happen due to low voltage.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

https://www.2carpros.com/articles/car-battery-load-test

If this checks out okay then I would tend to lean towards a body control module issue. It pretty much controls or is associated with each of the issues you are seeing.

Clearly I would want to check for codes first. Hopefully that will point us in the best direction. If you can't pull codes, most parts stores can pull them free of charge.
Image (Click to enlarge)
Attached Media
Feb 22, 2020 at 4:07 PM