Electrical weirdness -- Possibly solved

rph1982 · March 19

Hi everyone,

2022 Silverado 1500 LTD LT (pre-refresh) 2.7 and 8L90 -- 54k miles -- completely stock

I have some weird electrical issues, and I'm wondering if anyone can help me link to the problem. I'll have it diagnosed at the dealership, but they are more than 2 weeks out on any appointments.

This started for me a couple of weeks ago when the rear camera did not enable when I put it in reverse one morning. I got the "Service Vision System" message and a black screen when the truck was in reverse, and the same message if I manually enabled the camera through the screen interface. The truck was showing no other issues that I noticed (runs and shifts fine, no other electrical drama). After a little research, I ordered an OEM camera to see if that was the problem. I'm pretty sure it's not, and I have not installed it ... story continues.

I noticed later that the steering wheel heat was not coming on. The seat heaters work, but not the steering wheel heat.

Fast forward a week and about 500 miles, and I receive a check engine light. I check the code with my old dumb code reader and I have a P0650, P305C, P305E, and B2B0D.

Here is the funny thing: The check engine light does not immediately illuminate when the truck is started. When the light is NOT on, the camera and steering wheel heat do NOT work. HOWEVER, once the CIL illuminates (sometimes within a minute or two, and sometimes after several miles), both the backup camera AND steering wheel start working. If I use the code reader to clear the codes with the truck running, the light will go out and the wheel heat + camera will continue to work. The light does not come back on until the next start, and the process usually repeats.

Things I've thought about:

1) Ground strap recall. After receiving the letter, I checked out my strap and it is as green as a spring pasture. The dealer had none in stock and wouldn't for a while, so I put an insulated 4-gauge better cable on it. I can't tell yet if that's changing the behavior, but the light has come back a couple of times since then.

2) Could the battery be getting weak (it is original)?

3) I've read the service bulletin about wire chaffing, but some of that stuff is very hard to see without being familiar with the harnesses and having the truck up on a lift.

Questions:

1) Do the steering wheel heat and backup camera connect to a common module?

2) With the P0650 (check engine light circuit fault), is that trying to point me in the right direction?

3) Why would these functions start working the instant the CIL illuminates?

4) What else am I missing?

Thanks for any insight. The dealer mx situation is dire around here ... otherwise, this thing would be on a rack somewhere without me sitting here racking my brain.

Russ

GETGONE · March 19

You don't list where you live, but there's known issues with the ground strap behind the passenger side fender well liner.

https://gmauthority.com/blog/2026/02/some-chevy-silverado-1500-units-need-a-new-body-to-chassis-ground-strap/

silveradosid · March 19

there is a tsb which covers most of your codes chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://static.nhtsa.gov/odi/tsbs/2023/MC-10231640-9999.pdf

rph1982 · March 19

9 hours ago, GETGONE said:

You don't list where you live, but there's known issues with the ground strap behind the passenger side fender well liner.

https://gmauthority.com/blog/2026/02/some-chevy-silverado-1500-units-need-a-new-body-to-chassis-ground-strap/

Thanks for the feedback. I live in north Georgia. I bought the truck about a year ago, and it did have a short stint in road salt country prior to me owning it, so the frame has some rust spots.

In the original post, I mentioned the ground strap recall. I went to the dealer to schedule the service, and they are 2 weeks out on appointments, and they won't even make an appointment until they know when more straps will be delivered.

I went ahead and replaced my very corroded strap with a 4-gauge insulated battery cable for the interim.

rph1982 · March 19

4 hours ago, silveradosid said:

there is a tsb which covers most of your codes chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://static.nhtsa.gov/odi/tsbs/2023/MC-10231640-9999.pdf

Thanks for the feedback. I read through those TSB's. Mine does not exhibit any cranking issues. When the CIL light is on, it will not remote start, but there's no problem starting it from within the vehicle.

I went sifting through the wiring harnesses, but I could not see any chaffing or obvious damage at the pinch points mentioned in the bulletin. The strange thing to me remains the pairing of the reverse camera and the steering wheel heat ... those two not working until the CIL illuminates.

silveradosid · March 20

does your reverse light turn on when you put it inreverse

rph1982 · March 21

14 hours ago, silveradosid said:

does your reverse light turn on when you put it inreverse

Yes, it does illuminate when the truck is placed in reverse.

rph1982 · March 21

I think I am beginning to narrow down this issue, and it continues to be weird. I am still able to reproduce the symptoms on nearly every start.

--Crank truck

--No check engine light on, and no backup camera or steering wheel heat.

--truck is then put in motion and moves anywhere from a few hundred yards to a few miles

--check engine light illuminates (code check P0650, B2B0D, P305C, P305E)

--both accessories begin to work

I believe the check engine light won't come on and the accessories won't work due to a wiring and communication issue. I believe that due to the P0650. I have also noticed that my dumb scanner does not have "7EA" module listed when the accessories are not working. I know that's typically the TCM, but I know that's online because the transmission operates without issue (at least as well as you'd expect the janky ole 8L90).

** I have figured out how to make the CIL illuminate and get the accessories to work without moving the truck. After reviewing the TSB's about the KR73 ignition relay in the in-cabin fuse box on the passenger side, I started exploring this area. The TSB states to move the relays around a little to make sure they are seated. Occasionally, this would trigger the sequence to occur, but not every time. I unplugged the battery and then pulled that fuse box out of its mount (keep in mind there are 2 sides to it). I pulled the 2 massive wiring harnesses off of both sides to check for bent pins or corrosion. None found. I also pulled the smaller connector off, no significant findings.

After some experimenting, I have found that apply some pressure to the top part of the fuse box with the truck running, it will immediately trigger the sequence 100% of the time. I verified with over 10 start/shutdowns (closing the door and walking away from the truck for a few minutes to let it "go to sleep"). I identify the condition by looking at the CIL and keeping the center screen in camera mode with the "Service Vision System" message. When the sequence occurs, the CIL light will come on and the camera image immediately pops up.

So with this torquing and manipulation of the fuse block, is it worth buying a new block to see if the issue is internal to the fuse block itself? I'm sure these things are internally complicated, so a defect would not be unheard of. Maybe I've just been staring at this too long and I'm starting to go crazy. Part number is 84582037.

Thoughts? Thanks!

silveradosid · March 21

fuse block maybe, the fact you can can change how the symtoms change by pushing on the block still suggest wiring or connection. i would do a wiggle test on every wire in the plug that plugs in to the fuse block.

rph1982 · March 21

7 hours ago, silveradosid said:

fuse block maybe, the fact you can can change how the symtoms change by pushing on the block still suggest wiring or connection. i would do a wiggle test on every wire in the plug that plugs in to the fuse block.

I see your logic. I suppose I need to go to AllData to see if they have the pinouts for the connectors. There are 2 large connectors into the block, and 1 small one. I wonder if there's a way to pull part of the shell for those connectors off to check the actual pins. Because of the latching mechanism used, there's no way to get a probe into either of the connector bundles.

GMCustomerService · March 26

We're sorry to hear you're having electrical and engine light concerns with your Silverado. At this time, we'd like to connect further so we may investigate this further for you in an effort to resolve this situation. Please send us an email to [email protected]. Be sure to include "rph1982/GM Trucks Forums" in the subject line with these details. Your cooperation is much appreciated.

rph1982 · March 27

I'm not quite prepared to declare victory at this point, but I've made a positive step. I managed to get my hands on a GM electrical schematic/diagram and systems explanation document. It's huge (>1000 pages). I was able to look at the features having trouble (steering wheel heat, review camera, check engine light). The document does an excellent job of showing how features are grouped and powered.

It led me to the passenger-side cabin fuse block (as per my previous post). The document showed me that both of my problematic features route through the KR73 ignition relay, labled "K1" on the inboard side of the fuse block. The other features it powers are not installed on my truck -- trim level LT. That pretty well told me that the problem was with the voltage to the relay (wiring or connection), the fuse block itself, or a bad relay. I started with the easy part, the relay (part no. 13500126). I ordered a new one and installed it.

Upon installation and starting the vehicle, I saw the CIL illuminate, and then immediately go off (as expected). The camera and steering wheel heat immediately worked. I hooked up the code reader, and the codes resolved on their own. Yay, maybe.

I'm not sure if the relay just went bad, or if something caused it to go bad. Time will tell, but at least I know where to start. I'm going to return the camera I bought.

Hopefully, this helps someone else. The TSB I found online does allude to a possible bad relay, but no one else has posted about this issue that I can find.

GETGONE · March 27

At least it was hopefully a relay. On my 2008 Avalanche I had a weird issue where the rear doors would lock, but not unlock via the power lock switch or remote. Turns out the unlock for the rear doors ONLY was BUILT INTO THE FUSE BLOCK on the end of the dash! I had to buy a whole new fuse block to fix the issue. Luckily it was cheap used.