2015 Chevy Silverado Z71 CC (Stabiltrak Electrical Issue)

MBTX · September 4, 2019

Hello Forums,

Please help. My truck has experienced some on going electrical problems. I had video for the second dealership of the multiple issues as they are occurring and so far the truck is still doing it. Post repair it got better for two weeks but are now going back. First some background, then a time line of events, and then video.

I purchased the truck from the original owner in 2017 with 29K miles on it. Bought the most expensive aftermarket warranty from Dealership that sold the truck to original owner when I took it in to get looked over and serviced post purchase. The truck now has 56K miles on it. Here is a list of the issues and timeline sorted by year and mileage the best I can remember.

August 2017-29K miles_Purchased
November 2017-30K miles_
1. Trailer brake system error_Dealership replaced sensor_problem fixed
2. Flash ECM
3. Flash Radio Software - killed free XM...
4. Other recalls stuff
June 4th, 2019-53K miles_Electrical issue
1. As I am pulling into a parking space and coasting with foot on brake, truck steering dies, center console power dies, stereo off, AC off, driver cluster stays on. Then turns back on about 2 seconds later, hear a beap that sub and amp are back on through speaker chirp, AC comes back on with all other displays. This is as I am pulling in forward. I stop the truck, turn it off and turn it back on, drive around for 5 minutes and re park 10 times and can't get it to do it again.
2. I think its a fluke but the next day I can't get my truck to start so the original battery is deemed dead. I change it out for closest match with higher cold cranking amps at Auto zone and I am back to driving.
June 22nd, 2019-54,360 miles_Electrical issue
1. As I am pulling into my drive way and going about 3-6 MPH as soon as I straighten my wheels, and about to come to a stop, my internal displays, AC, stereo radio screen turn off, driver cluster un affected. The truck is still on and running from the engine standpoint, but power steering is off. I turn the truck off and restart, voltage on the battery indicator goes from lower end of middle range bar to a little past highest rating on middle range bar. I drive around to to see if I can get this issue to come back but it wont.
July 10th, 2019-55,255 miles_Electrical issue
1. Same thing as before, making a low speed turn applying brakes into a parking spot and all power to cab interior dies, then comes back on. Drive around but cant get it to have the issue.
2. Take to first Chevy dealership, they run codes off my story, have it for the a day and a half, and claim they can't find anything wrong with it.
August 2, 2019-55,911 miles_Electrical issue
1. Same thing as before, however this time I am in a parking lot trying to go into a spot, I have to reverse and thats when all heck breaks loose. I get:
  1. Stabilitrak Service Warning
  2. Bells dinging like I just got into my car and put key into ignition.
  3. Rear Parking assist symbols unavailable on nav screen, more bells dinging
  4. Park Assist off warning
  5. Put in park and everything looks fine and normal, people watching me are like why is this idiot pulling into and out of parking space over and over
  6. I put it in reverse and information warnings continue, with parking assist, issues, stabilitrak issues, driver cluster still on, but AC off, and center console off, power steering off, truck engine still running.
  7. Finally after about the 4th time going back and forth into the spot, the truck completely dies and I have to turn the key off, and restart the truck in the middle of the parking maneuver. I drive it around for 10 minutes and seems fine now.
  8. Thankfully I had video of the entire thing because I began to sense when I thought it would happen.
2. I take the truck and video to Chevy dealership, within 20 minutes they have hooked it up and diagnosed the issue:
  1. Battery good
  2. alternator good
  3. everything else good
  4. Negative battery cable bad.
    1. Reason shown on test
      1. Negative Battery cable has 420mv voltage drop, drop spec is 180 mv. All codes given are low voltage codes
  5. Repair was to replace this.
3. While all this was going on I also had a power steering flash required from Recall that was completed.
August 10, 2019-56K miles_electrical issue
1. Same as prior but only made some dings and stabilitrak but things were better I guess.
August 13, 2019-56K miles_Electrical issue
1. Same as prior
August 30th, 2019-56K miles_Electrical issue
1. Okay enough is enough
2. This time as I am pulling into my sons school to drop off lunch, the truck goes bananas, stabiltrak, park assist, AC off, and now the power steering is dieing and the truck is not running right and my left hand get stuck in the steering wheel and the wheel racks hard left and I hurt my arm... I got video. Much more violent power steering issue post flash.
3. I drive straight to Chevy dealership drop off.
September 3rd, 2019-56K miles_electrical & power steering issue
1. Get a call around 3:00 PM from Dealership (that originally found negative battery cable issue.) telling me they are running the diagnostic test but nothing is popping up.
September 4th, 2019-56K miles_Electrical Issue
1. Dealership rep called and said, they performed extensive testing and now are getting this. The negative battery cable is showing the incorrect amount of resistance therefore they are again deeming the negative battery cable to be the culprit.

Sorry on the video, I had to trim it down from the latest video to show what happens due to forum restrictions. You will see though that as I am turning the wheel and as the issue happens the battery indicator moves down sharply and then comes back up.

Has any one else dealt with something similar and if so what was the cause? Any electrical guys out there agreeing with the test results?

Thanks,

MB

woychc · October 1, 2019

I had some stabilitrak issues as well on my 2016, there were over 2 pages of electrical fault codes stored when the dealership scanned it. They replaced a bunch of harnesses, etc and in the end found the neg battery cable to be the issue. It was replaced and all issues have gone away. I was told by them that this is fairly common on the 15 & 16s.

MBTX · October 1, 2019

Thank you woychc for the response.

Update is the truck has started turning off again this time while it’s moving in a between 12-25 mph. It died yesterday in an intersection going about 7 mph from stop while turning left. All while recording so I am sending that to corporate with the other videos. The dealership also has the videos.

I have opened a case with Chevy corporate warranty and they are trying to work with the dealership to get an engineer onsite. The dealership in North Richland hills can’t get me into a loaner until 10/09 and won’t pay for a rental so I’m stuck driving the car.

I suspect the truck will go back in and they will get yet another page of low voltage codes telling them to change negative battery cable which I’m not going to accept if they claim that’s the reason. I’m on my third...

Very upset Chevy!

movario · October 1, 2019

It all sounds like a voltage issue. "Battery good and alternator good"? How were they tested?

MBTX · October 1, 2019

Thanks for the Reply Movario.

The dealership doesn't specify the exact test they do. The paperwork shows "tested electrical system, negative battery cable shows to be faulty" and the reasons given above are what's written down about resistance etc. I have asked about the alternator and battery each time I am at the dealership and the answer is that they have tested fine.

The only fix I can do to keep the truck driving when it starts to fail and lose power to various systems, is turn it off and then back on again. The battery indicator shoots up to almost full 14, then slowly creeps down until it starts to fail. I replaced the battery on June 4th as that was what initially was diagnosed.

I'm hoping the dealership and Chevy can team up with an on-site engineer and get to the bottom of this issue as its becoming a safety issue now that the truck is turning off driving down the road and doing turning maneuvers above 5 MPH. Prior instances of total power failures happened during low speed parking maneuvers that sent the stabilitrak, parking assist, trailer brake issues into total shorts. The condition would appear to be getting worse.

movario · October 1, 2019

Are faultcodes reading "voltage to low" or "voltage to high"? Could be an issue that the voltage goes to high from time to time, so all the ecus are starting to switch off.

sk · October 1, 2019

That is definitely the bad battery cables or ground issue. Tell your dealer to look up PIT5405. I attached an old copy but there is probably a newer revision by now.

PIT5405B Electrical Ground.pdf

MBTX · October 1, 2019

Movario - the service manager at the dealership said in text to me on Friday August 2nd, that "all codes are low voltage codes, negative battery cable has 420mv voltage drop, spec is 180mv. Battery tested good" That was the original diagnosis and the same was repeated when they changed the cable again on September 4th, only this time they added a resistance issue to the cable as an manufacturer defect from supplier. Its all still happening.

sk - I will forward this to the Chevy dealership. After speaking with GM corporate today, they said the dealership is not responding to their requests and they are escalating the case up. It's very frustrating to say the least but I hope they can come together and figure this out.

MBTX · December 12, 2019

Update:

Chevy Dealership determined that the low voltage codes are coming from the aftermarket sound system (200W Amp) installed which ran for 1 year with no issue, and due to the installation of large 34" tires and rims that originally came installed on the truck when sold from the Chevy Dealership that ran for 4 years with no issue.

The dealership disconnected the sound system at the battery and said that was the issue. BestBuy took the receipt from me that showed the sound system was at fault and pulled the entire thing out. They found no issues with the installation and credited me part of the original install price and didn't charge me for the removal. Thanks BestBuy Corporate.

Now fast forward 3 weeks, the truck continues to struggle with staying on and died last night turning into my driveway. Same thing as before, stabilitrak warning, headlights dimm etc and truck dies while making a slow speed turn while engine is in idling into turn with brakes engaged. The dealership claims that the alternator, negative battery cable, and charging system are fine. I had Chevy corporate involved but it didn't help much. I am going to reach out to the Chevy dealership here locally for one last ditch effort to fix the truck, otherwise I will be trading it in for a new competitors truck.

Eli H · December 13, 2019

I had a similar issue with my 2015 Sierra Denali.... the gauges were going up and down , gas, oil, battery and everything on the cluster was going crazy. It would say “ service airbag” park assist off and it would also say my parking break was in and beep for a while. My AC would not work, it wouldn’t even light up. So the dealer wanted to charge me $890 to diagnose the issue so I obviously walked out and went to a mechanic that changed the AC module for $200 and solved all the issues for now. Hope this helps.

movario · December 13, 2019

I would love to take a look at it. The way I would go is to take an oscilloscope and measure the 12v supply the 5v supply and ground when the shutdown happens, to find out if they`re really getting low voltage. And that way I would work "along the cables and ecus" to find the error. There are many possibilities. It could also be a sensor that has a short circuit from time to time that lowers the voltage. But its difficult without looking at it.

MBTX · December 20, 2019

Thank you Eli and Movario.

The truck has been at the dealership for a week and I am in a new car loaner. Here was the update I received yesterday.

Pulled codes and found low voltage codes for Radio, radio controls, and HVAC controls. No other codes set. The codes that are set will not cause the truck to die/stall. Test drove and could not duplicate. Called TAC and told them everything I have done. They instructed me to get the truck to die/stall and look at the operating voltage of the steering gear. The steering gear may be overworked due to the lift and oversized tires and causing power steering to steal power from other systems in the truck. A technical assistance case (TAC) has been opened with GM.

I have told the dealership that you will here the stereo cut in and out 1-2 times in the first 5 minutes of driving, at that point the trucks voltage will start to struggle. Repeated parking maneuvers, idling at lights, etc will drive the voltage down. At that point once you have worked the truck a little, the head lights will start to dim at idle at stop lights without moving. Then during slow speed turning maneuvers you can get the truck to die. You can start to get a sense of when it will happen as you continue driving the truck.

The only positive thing I can say is that the dealerships demeanor this time around has actually improved 200% with almost daily updates. It was unexpected to say the least.

My neighbor has a lifted 2015 Silverado with 101k miles almost identical to my setup and he's had absolutely no issues. The difference is his is a 2500 and he has a dual battery setup. The dealership stated last time we were there that they believed if I spent $1300 on a dual battery setup similar to the 2500 that it would fix the electrical issue which they still claim is due to the tires and lift which Chevy Grapevine installed when they sold the truck. Other shops claim its the alternator. I see so many trucks lifted with sound system and am really scratching my head why this is the go to excuse the dealership keeps giving.

Hoping they can find the issue and get me back on the road as I don't like driving the rental car. Are lemon laws applicable in my situation? Its just so silly to me that the truck ran fine for 3 years lifted and add another full year and a half with a sound system and lift, then all of the sudden the battery dies, I replaced with a similar model from the autoparts store and here we are.

MBTX · January 10, 2020

Alright update from Chevy of North Richland Hills after having the truck for 2 weeks and opening a TAC was that the original diagnosis of it being the aftermarket sound system, which was pulled by Bestbuy, was incorrect and its actually the fault of the larger tires (34") and wheels (22") that came installed on the truck from Grapevine Chevy when purchased new... They are getting low voltage codes from the steering assist system which is causing the voltage and amp drops when turning at low RPM which will kill the truck. The dealership drove the truck for 7 miles and said they couldn't replicate the issue so its fine. The truck was given a completely clean bill of health and the dealership doesn't want to deal with it. Gonna have to trade it in because I can't get any support from Chevy to fix. GG Chevy

Edited January 10, 2020 by MBTX
Typo

movario · January 10, 2020

So if I understand that correctly, they found out that the larger wheels are the reason for your issues? So that the "force" needed to turn those wheels is too much so that the system voltage drops and all the ecus switch off?

You`re going to trade it in and leave it like this?

ChrisDM · August 28, 2021

Having the same issue with my 2015 Silverado 1500 Z71. It seems like the issue has progressively gotten worse. Took it to the dealership and they ran diagnostics and charged me around $2000 to swap out some electronics including the negative battery cable. Since then the issue has persisted and gradually worsened. The vehicle will lose power momentarily when I hit the brakes driving at speeds up to 60mph. All electronics and lights will flicker and come back on. When parking and turning at low speeds, the vehicle will completely lose power and sometimes shut off entirely and need to be turned back on.