2022 Duramax Trailer Brake Disconnect Warnings With Solar On

[DJC]

I recently went through a great deal of down time due to the brakes on my fifth wheel having some issues and both the RV maintenance team and my GM dealer hadn't any idea on how to diagnose and take care of the issue. I tow with a 2022 Duramax 2500 HD. The computer in the truck indicated that the trailer brakes were disconnected periodically while towing. This eventually led to the trailers brake module going out. My trailer had been in the shop (dealer, due to extended warranty policy) for most of the summer due to the insurance company not heeding the findings and recommendations of the techs at the dealer. So; after a new harness and some sort of relay, they finally replaced the actual module which took care of that particular problem. After picking up the RV and getting up the road for about 40 miles, I started getting errors again via my trucks computer. I again called both the RV dealer and the GM rep. Neither one wanted to try and guess what was wrong. I did some investigation and found that there is indeed some problems with this particular scenario noted mainly by GM but not with my particular truck. That is why GM wasn't able to see anything on there end. The problem is that when the solar is switched on for the RV to charge the batteries, it sends a slightly higher charge through the trucks trailer brake power control module and the trucks computer interprets this as a ground fault. So if you turn off the solar switch on the RV you won't have a problem. The fix for this issue is to replace the original module (part no. GM 23306694) with GM 85073615 and you can leave the solar power on while driving. The new module cost me about $34.00. If you or someone that you know that can work on vehicles, this is a fairly easy task/job. Which will save quite a bit of money. The hardest part for me while doing this is that I have some arthritis so it took me about three times as long as it would have when I was a tad younger. Good luck out there

 

[poohbear]

Are you referring to the ABS module on the RV brakes or do you have Disc brakes ? Ive read about this GM problem on other forums.

 

[DJC]

The Bosch brake system module is what needed to be replaced in the RV. And, yes it is required for a towable ABS due to the electric drum brakes. The module is the brains for it. It is one of the components that are not easily accessible. Apparently; the thinking is that there shouldn't be much need to access it. As I mentioned earlier, the insurance company didn't want to believe the service techs about it so I can only guess that either they never heard of such a thing or they wanted to see if I blinked first so that they could deny my claim. It is my understanding that the cost for this particular module is from $1,200 to $1,800. So it's conceivable that the insurance company was pussy footing around the real issue due to what the entire repair bill ended up being. I hope this answers your question. If anyone has the same issue while towing with the solar on, I would start with, try towing with it turned off and go from there.

 

[RyanBGood]

It has NOTHING to do with solar panels. I know everybody says that because it has been fed to them as an excuse from GM, but the reality is GM doesn't have a clue either.

I dealt with this issue for years: 2020 Chevy 3500, 2022 Solitude 390RK with disc brakes. The "trailer brakes disconnected" issue happened relatively often. The only solution was for me to pull over, disconnect the trailer pigtail, reconnect and continue down the road.

I DID NOT HAVE SOLAR PANELS!

 

[jkwilson]

It has NOTHING to do with solar panels. I know everybody says that because it has been fed to them as an excuse from GM, but the reality is GM doesn't have a clue either.

I dealt with this issue for years: 2020 Chevy 3500, 2022 Solitude 390RK with disc brakes. The "trailer brakes disconnected" issue happened relatively often. The only solution was for me to pull over, disconnect the trailer pigtail, reconnect and continue down the road.

I DID NOT HAVE SOLAR PANELS!

While yours may have had nothing to do with solar, it is very common for some years of GM products to have a well documented problem with solar panels and lithium batteries. There is a TSB and an upgraded trailer control module that fixes the problem.

 

[DJC]

I am sure that you indeed had a connectivity issue. I'm sure that is sometimes common. You probably shouldn't confuse that and the technical issue that is happening as a result of what has been described.
GM indeed does know of a problem as I pointed out. GM updated the module and issued specific Technical Service Bulletins (like TSB 23-NA-149 or Recall N232414840), most service advisors didn't know the computer was programmed to be hyper-sensitive to incoming voltage. I would think that many rvers have had situations such as you describe and as you might guess, that was one of my first thoughts as well. But is was beyond that and now I am able to tow with out any issues. If it were me with a connectivity issue that is plaguing you, it might be a good idea to invest in a higher quality connection so that you won't need to pull over and reconnect constantly. Good luck

 

[RyanBGood]

First, it IS well documented, I agree. It's been documented for years by many people, and GM has continually blamed "solar."

And, although some of ya'll believe them without question, that doesn't fit because many have the problem in different configurations; lithium + solar, lithium only, solar no lithium. Just because GM says that solar is the problem doesn't make it so. They're using that as an excuse (a type of customer blaming) cause they can't come up with the true cause, but it doesn't fit every situation wherein the problem is manifesting itself. That's FACT.

2) I know all about the TSB. GM and I fought over the TSB for months. The TSB you're referring to (TSB 23-NA-149 - dated September 2023) only applies to 2024 year model Silverado.

In July 2024, there was a "Customer Satisfaction Program" (N232414840 was NOT a recall) that stretched back to cover 2020-2024 year model trucks with the integrated trailer brake controller.

Only, amazingly, when GM ran VIN numbers, they found that it didn't apply to MY 2020 3500 w/ the integrated trailer brake controller (AND documented history of his problem) for some reason.

Ultimately they (at the corporate level) could never explain to me why my 2020 truck with this exact problem wasn't eligible for a "Customer Satisfaction Program" that applied to 2020 trucks with this exact problem, but in the end my VIN wasn't listed so ... I got a giant "go pound sand" from GM.

(The Customer Satisfaction Program says "The fix is to be applied to all affected 2020 and 2024 Chevy Silverado HD trucks, regardless of current ownership, free of charge to the owner." Yet somehow they wouldn't cover the work for me.)

3) The solution doesn't ALWAYS fix the problem. Friends of mine, some on this very forum, have had the module replaced (one of them had it replaced twice) and it didn't fix it.

By the way, a simple search of other forums will show some people who had the new module installed and their problems got WORSE!

On the Duramax forum, on a survey with 20 participants, 14 said that the new module did not fix the problem. (I don't really trust that survey cause I don't know really what people were answering versus what they THOUGHT they were answering. But it's still an interesting piece of circumstantial evidence.)

4) Assuming solar panels ARE the problem, GM still can't explain why some of their vehicles pulling trailers WITHOUT solar panels also have the "well documented" problem. They're simply just disregarding those as "unexplainable" as it appears you're doing.

5) Oddly enough, after I swapped my 2022 Solitude that had NO panels for a 2025 Solitude WITH panels, I NEVER had that problem.

I only had the 2025 trailer for about six months, so one could say that it was coincidental and that I just didn't have the rig long enough for the issue to manifest itself. I did pull the rig about 8,000 miles in those 6 months.

Regardless isn't it odd that I had major problems (and often) with a trailer WITHOUT panels and then didn't have a single instance with a trailer WITH panels, all with the same truck, and yet everybody is convinced that solar charge controllers are the DEFINITE problem ... because GM said so?

Good for those who are no longer seeing issues. Hopefully it doesn't come back. For some is HAS!

I assure you all, I'm not a sample size of ONE. I chased this problem for years!

(Actually, in my data gathering, I found LiFePo4 setups to be more common amongst those of us with this problem than solar installations. Though, I still documented instances with lead-acid batteries, so I couldn't point to lithium batteries definitively either. The only irrefutable common factor in all of this is GM!)

All I'm saying is GM doesn't quite have their heads wrapped around the issue as much as they say and as much as many of you think they do.

They are TELLING YOU that they have it figured out, but there is much more to this issue than you realize.

I accept that that some sort of "voltage transients" in the configurations that MAY include solar for some people is the root cause. But WE ALL can NOT spread the misinformation that simply "solar" is to blame because the problem is bigger that.

I'm just saying ... everyone's mileage may vary. That's all.

 

[Les R]

I recently went through a great deal of down time due to the brakes on my fifth wheel having some issues and both the RV maintenance team and my GM dealer hadn't any idea on how to diagnose and take care of the issue. I tow with a 2022 Duramax 2500 HD. The computer in the truck indicated that the trailer brakes were disconnected periodically while towing. This eventually led to the trailers brake module going out. My trailer had been in the shop (dealer, due to extended warranty policy) for most of the summer due to the insurance company not heeding the findings and recommendations of the techs at the dealer. So; after a new harness and some sort of relay, they finally replaced the actual module which took care of that particular problem. After picking up the RV and getting up the road for about 40 miles, I started getting errors again via my trucks computer. I again called both the RV dealer and the GM rep. Neither one wanted to try and guess what was wrong. I did some investigation and found that there is indeed some problems with this particular scenario noted mainly by GM but not with my particular truck. That is why GM wasn't able to see anything on there end. The problem is that when the solar is switched on for the RV to charge the batteries, it sends a slightly higher charge through the trucks trailer brake power control module and the trucks computer interprets this as a ground fault. So if you turn off the solar switch on the RV you won't have a problem. The fix for this issue is to replace the original module (part no. GM 23306694) with GM 85073615 and you can leave the solar power on while driving. The new module cost me about $34.00. If you or someone that you know that can work on vehicles, this is a fairly easy task/job. Which will save quite a bit of money. The hardest part for me while doing this is that I have some arthritis so it took me about three times as long as it would have when I was a tad younger. Good luck out there

I have a 2024 Chevy and I had to buy a 7 pin adapter so my truck could see the trailer all the time because of the pulse width Chevy does with lights. I am sorry but I don't have the part number. I dis try several other possible solutions that didn't work out.

 

[Steve-s RV Planner]

This has been helpful. I was unaware of the Customer Satisfaction Program. I have a 2022 GMC 3500 HD Denali and have experienced this problem several times with my old and new campers, always thinking it was a loose connection somewhere in the truck. With my old camper (2014 34' Coachmen Chaparral Lite 5th wheel, no solar, 2 lead acid batteries) I would connect in the sidewall of the bed. With my new camper (2026 Grand Design Momentum 350G, with solar & 2 100 AH Lithium batteries) I connect to the bumper as I also installed the GMC back-up camera on the Momentum. Not only do I get the intermittent brake disconnected message, but I also frequently get the trailer camera not found message.

 

[Dutchman2]

Had the trailer disconnect warning issue w/o solar and lead acid battery shortly after taking delivery of our new truck. I saw the SB come out and GM sent out a warranty notice to replace the trailer controller. Had the dealer do it under warranty and have had no further issues.


Dutchman2

 

[poohbear]

maybe ya'll should try a Ford

 

[RyanBGood]

maybe ya'll should try a Ford

Actually, I was gonna mention it before but decided not to.

I haven't really looked into it much cause I didn't have a Ford, but I have seen multiple threads on different forums that there has been some sort of similar issue with the trailer brake controller in some Fords.

I don't know the nature of the issue or the circumstances, but it's worth keeping an eye out.

 

[poohbear]

Actually, I was gonna mention it before but decided not to.

I haven't really looked into it much cause I didn't have a Ford, but I have seen multiple threads on different forums that there has been some sort of similar issue with the trailer brake controller in some Fords.

I don't know the nature of the issue or the circumstances, but it's worth keeping an eye out.

ford fixed its issue with a simple software update that on my truck was done over the internet parked at my house. I never had any problems on either my 2022 or the 2025. The issue on the GM's seems to be from my reading is the higher voltage of Li batteries and/or the solar charging voltage , the trucks brake module doesn't like this slightly higher voltage. The peak charging voltage of an AGM could also do this.

 

[RV2600RB2]

First, it IS well documented, I agree. It's been documented for years by many people, and GM has continually blamed "solar."

And, although some of ya'll believe them without question, that doesn't fit because many have the problem in different configurations; lithium + solar, lithium only, solar no lithium. Just because GM says that solar is the problem doesn't make it so. They're using that as an excuse (a type of customer blaming) cause they can't come up with the true cause, but it doesn't fit every situation wherein the problem is manifesting itself. That's FACT.

2) I know all about the TSB. GM and I fought over the TSB for months. The TSB you're referring to (TSB 23-NA-149 - dated September 2023) only applies to 2024 year model Silverado.

In July 2024, there was a "Customer Satisfaction Program" (N232414840 was NOT a recall) that stretched back to cover 2020-2024 year model trucks with the integrated trailer brake controller.

Only, amazingly, when GM ran VIN numbers, they found that it didn't apply to MY 2020 3500 w/ the integrated trailer brake controller (AND documented history of his problem) for some reason.

Ultimately they (at the corporate level) could never explain to me why my 2020 truck with this exact problem wasn't eligible for a "Customer Satisfaction Program" that applied to 2020 trucks with this exact problem, but in the end my VIN wasn't listed so ... I got a giant "go pound sand" from GM.

(The Customer Satisfaction Program says "The fix is to be applied to all affected 2020 and 2024 Chevy Silverado HD trucks, regardless of current ownership, free of charge to the owner." Yet somehow they wouldn't cover the work for me.)

3) The solution doesn't ALWAYS fix the problem. Friends of mine, some on this very forum, have had the module replaced (one of them had it replaced twice) and it didn't fix it.

By the way, a simple search of other forums will show some people who had the new module installed and their problems got WORSE!

On the Duramax forum, on a survey with 20 participants, 14 said that the new module did not fix the problem. (I don't really trust that survey cause I don't know really what people were answering versus what they THOUGHT they were answering. But it's still an interesting piece of circumstantial evidence.)

4) Assuming solar panels ARE the problem, GM still can't explain why some of their vehicles pulling trailers WITHOUT solar panels also have the "well documented" problem. They're simply just disregarding those as "unexplainable" as it appears you're doing.

5) Oddly enough, after I swapped my 2022 Solitude that had NO panels for a 2025 Solitude WITH panels, I NEVER had that problem.

I only had the 2025 trailer for about six months, so one could say that it was coincidental and that I just didn't have the rig long enough for the issue to manifest itself. I did pull the rig about 8,000 miles in those 6 months.

Regardless isn't it odd that I had major problems (and often) with a trailer WITHOUT panels and then didn't have a single instance with a trailer WITH panels, all with the same truck, and yet everybody is convinced that solar charge controllers are the DEFINITE problem ... because GM said so?

Good for those who are no longer seeing issues. Hopefully it doesn't come back. For some is HAS!

I assure you all, I'm not a sample size of ONE. I chased this problem for years!

(Actually, in my data gathering, I found LiFePo4 setups to be more common amongst those of us with this problem than solar installations. Though, I still documented instances with lead-acid batteries, so I couldn't point to lithium batteries definitively either. The only irrefutable common factor in all of this is GM!)

All I'm saying is GM doesn't quite have their heads wrapped around the issue as much as they say and as much as many of you think they do.

They are TELLING YOU that they have it figured out, but there is much more to this issue than you realize.

I accept that that some sort of "voltage transients" in the configurations that MAY include solar for some people is the root cause. But WE ALL can NOT spread the misinformation that simply "solar" is to blame because the problem is bigger that.

I'm just saying ... everyone's mileage may vary. That's all.

Calm down dude.