21' Suburban HC - Electronics went bananas.

[MrScrewzloose]

Hey All,

I figured I'd drop a note here just in case someone else had gone through this issue and worked through to resolution. Unfortunately, my local Chevy dealer's service department is way behind, earliest I can get in is almost a month out.

my truck: 2021 Suburban HC 6.2L

What happened?

- Yesterday morning, started the truck as normal, got a Low Battery Warning and also got a Service Driver Assist System error. From the looks of it, my lane assist and forward camera system stopped working. Later that morning, 2nd restart, same errors.

- I went home, checked the battery, was showing about 12.46v, low but not terrible. Disconnected all the vehicle leads to the battery and put the battery on a charger.

- Came back about 2hrs later, charger showed it was in float mode and the battery was fully charged. Reconnected all the vehicle leads to the positive/negative. Started trucked and now in addition Service Driver Assist System error, my entire Infotainment screen is black and the controls below are no longer illuminated. Turned the truck off, exited vehicle, then re-entered and restarted and every error in the book began to flash on the dash screen. So many errors.

- I came back to the truck a few hours later. Truck refused to crank. Numerous errors popped up again. I pulled on my OBDII scan system, over 43 fault codes across 14 systems.





- In my 2016 Tahoe, I saw a similar issue with a dieing battery causing an array of electronic malfunctions. So I replaced the battery. I no longer get the array of errors, however, my Infotainment system still does not power on. Nor do I have sound when my indicators/blinkers are used (I wasn't aware the indicator sound was piped through the speakers). I've attempted every button "reset" procedure I could find on the internet but nothing worked.

- I've done a continuity test on every fuse in the engine bay, passenger side, and rear. Nothing blown that I could find.

Question:

- Anyone know where the modules are located that serve as the hub for the Infotainment center?
- Any bright ideas?


Thank you!

 

[StephenPT]

So at this point you've replaced the battery, everything is back to normal except the infotainment screen won't boot and you don't have a blinker sound?

Have you tried using the physical buttons just below the infotainment screen? There's a power button, home button, skip track, etc. Can you get any of those buttons to turn on the radio, or screen? I know in my Honda Accord when I replaced the battery the infotainment screen was locked out. Doing a bit of searching I found that pressing and holding the power button resynced the infotainment with the car and unlocked it.

I believe the radio/infotainment module is located to the outboard side of the glovebox.

 

[MrScrewzloose]

Thanks.

At this point, the Infotainment system does not power on. The physical buttons below, as you mentioned, power, home, skip, etc. Do not function either, nor do they illuminate. I've pressed every reset combo on those buttons I could find without success.

As for the indicator/blinker, those do still work, but the audible "clicking" sound you generally hear when using them does not. I guess those are tied into the audio system/speakers.

 

[StephenPT]

Might just need to take it to the dealer and get the radio reprogrammed?

https://static.nhtsa.gov/odi/tsbs/2021/MC-10197327-9999.pdf

 

[MrScrewzloose]

Might just need to take it to the dealer and get the radio reprogrammed?

https://static.nhtsa.gov/odi/tsbs/2021/MC-10197327-9999.pdf

Yea, this may be the case.. but given I can't get into service till mid-December, was seeking alternative resolutions.

 

[Doubeleive]

disconnect battery again and re-try, this time when you have the cables off either touch the cables together for a few seconds and/or just go inside the truck and hit every button/switch/pedal to dissipate any remaining power, then reconnect the battery.

I would guess the radio (mostbus) probably did not get a good handshake when the power was disconnected the last couple times.

 

[RST Dana]

Yea, this may be the case.. but given I can't into service till mid-December, was seeking alternative resolutions.

Ouch. I’m spoiled with my dealer. I don’t have to wait for appointments. If I thought there was going to be an issue, I call the service mgr before I head there.

 

[StormTrooprSubZ71]

Yea, this may be the case.. but given I can't get into service till mid-December, was seeking alternative resolutions.

No other Dealers close by? My local dealer was backed up 3 weeks for any service. A dealer 20 minutes away took me in the next day.

 

[MrScrewzloose]

disconnect battery again and re-try, this time when you have the cables off either touch the cables together for a few seconds and/or just go inside the truck and hit every button/switch/pedal to dissipate any remaining power, then reconnect the battery.

I would guess the radio (mostbus) probably did not get a good handshake when the power was disconnected the last couple times.

I gave it a go, no dice. Unfortunately.

No other Dealers close by? My local dealer was backed up 3 weeks for any service. A dealer 20 minutes away took me in the next day.

There's two others in the area; however their reviews are abysmal.

 

[Doubeleive]

I gave it a go, no dice. Unfortunately.



There's two others in the area; however their reviews are abysmal.

ya your code list is showing the open code for telematics, you might try digging around the web for where the radio grounds are and fuses, might get lucky