New 2020 Suburban w/775 miles - loss of steering assist, all gears but 1, etc.

[JohnnyR]

Man - I must have won the prize for dud purchase! I'm open to any and all suggestions for how to deal with this:

Long time Chevy purchaser/owner here. Just picked up a new 2020 Suburban LT w/5.3 in late January '20. Less than two weeks and 800 miles into ownership, it threw multiple codes upon start-up.

I lost steering assist, StabiliTrak, all gears but 1st (no reverse, no manual shift mode), tow/haul mode, trailer brake system, seat heat. The tach and speedometer were inop as well (just stayed pegged to the bottom).

Five minutes and six restarts later, it ran fine. Called dealer and arranged to bring in the next morning. Next morning, same issue upon start. Approximately twenty attempts and still in limp mode, so arranged for tow. Turned truck to "on" a few minutes later in order to read mileage and no codes exhibited, so I started it without issue and drove to dealer.

The dealer's maintenance crew can't reproduce the issue and they are unwilling to simply replace ECM's/TCM's.

Sigh... I have a feeling I'm in for a nightmare of chasing electrical gremlins. It's supposed to be our family vehicle for travel to camp up in northern Maine. No way am I trusting this thing with my kids or back in the sticks, with all the potential for failure engineered into the electrical system. After now reading here on this forum about the steering and electrical issues of this platform, I'm pretty bummed at the ownership ahead of me.

You can read my NHTSA ID Number: 11307573 report at this link. https://www.nhtsa.gov/vehicle/2020/CHEVROLET/SUBURBAN%25201500/SUV/4WD
Thanks,
Johnny
Boston, Massachusetts

 

[Doubeleive]

my best suggestion would be next time it happens pull out your phone and record it, that way you have some evidence to show

 

[JohnnyR]

Will definitely do that...

 

[Doubeleive]

Will definitely do that...

You shouldn't be having these kinds of issue's on a brand new truck but they are known to be finicky when there is power problems, such as a bad battery or battery cables, there are some TSB's out there for similar or related issue's, a TSB is not a recall but is a technical bulletin that they put out to the tech's when they find a potential issue, some of them involve replacing battery cables and others are checking various connections or even a "calibration firmware update".

 

[gat0r]

you need to talk to service manager & have them get a competent mechanic to look at it.
sounds like they had an oil change monkey look at it

should be codes stored in the system.

there are known TSBs for steering.
have them check for grounding issues. (cut wires, loose connections)

 

[JohnnyR]

Hopefully it's gone higher than the bottom tier mechanics. They've had it for three days.

I forwarded the VIN of a similar NHTSA case of a 2019 Tahoe w/exactly same symptoms. They should be able to research and find the issue between that and the TSB's. Maybe...

you need to talk to service manager & have them get a competent mechanic to look at it.
sounds like they had an oil change monkey look at it

should be codes stored in the system.

there are known TSBs for steering.
have them check for grounding issues. (cut wires, loose connections)

 

[JohnnyR]

Good news: they tried starting it with remote start this a.m. and all failure modes exhibited, so they are actively checking to see where errors are generating.

 

[JB11]

Good news: they tried starting it with remote start this a.m. and all failure modes exhibited, so they are actively checking to see where errors are generating.

Keep us updated

 

[GTNator]

Hopefully it’s just a software issue that can be fixed with a fresh flash of the computer.


Sent from my iPhone using Tapatalk

 

[JohnnyR]

Communication module (for Onstar and remote start) that went tango uniform.
Pretty lame that a non-essential feature failure could make entire vehicle inop.
Never again am I buying a modern vehicle for camping, road tripping in backwoods areas, etc.