Power Steering Failure / Electrical Shutoff

bowtieman · April 10

Ok, for a first post, this is going to sound like I'm crazy for that I apologize, but not sure where else to turn (other than a dealer >_< ).

I have a 2018 Silverado 1500 with a lift and some 35s. When I was turning hard to the left before backing into my driveway as I always have, my power steering felt really sluggish, but I also noticed that the Car Play screen went black. I was listening to music at the time and it stopped playing. My Dash lost power for a second and when it returned I had a Stabilitrak error but no Check Engine light.

I only mention the 35s as I have heard that the larger tires will put more wear on the steering assist system. So I'm expecting some failure there but the electrical symptoms are throwing me off.

The odd thing is the electrical failure also happened about 2 months ago while going straight down a local street. That time I pulled off the road and turned on the hazards, but nothing happened. I pulled the truck safely to a stop on the side of the road and waited about 5m while I went to check battery connections etc. After about 2-3m I heard an audible click as the hazard relays started working (lights blinking) and it seemed the system reset itself and I was able to fire it up, hazards started working etc. I've had the battery checked and it seems fine, charge/cranking amps etc. About to grab a better code reader as the $100 basic one I have doesn't show anything.

Again, I apologize for the "What in the tarnation is this young buck smoking?!?!" post but all my combing and reading has found nothing so far.

asilverblazer · April 10

I would thoroughly check all grounds and cables, not just at the battery.

ftwhite · April 10

Almost every electrical issues I have had with the four GM trucks I have owned have been traced to poor grounds. In two cases, several trips to the dealer didn’t resolve the issue until they just replaced the main battery ground. I did this on my 2018 Silverado as well when it started showing signs and all is well since. Testing the connection and testing the resistance on the bench didn’t show a consistent issue, but replacing the cable fixed the problem.

bowtieman · April 22

Thanks @asilverblazer & @ftwhite!

Took another look and found a loose nut! And a great explanation of the intermittent issue. Oddly enough it didn’t wiggle, but the truck acted up and threw on a multimeter and boom found it!

Thanks again yall. We will see how it runs over the next few weeks.

sk · April 26

Also look for GM bulletin PIT5405. It's been through many updates do I don't know what revision is the latest (it will have a letter at the end). It covers known ground issues as well as some other electrical things to inspect.

If you use the search bar in the upper-right of the forums you will find a whole bunch of threads about the electrical issue ....