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This is a long story but covers my 3 month experience dealing with GM and their customer service line to repair a major electrical issue I was having with my 2019 Z71 Colorado. In the end, I felt I was forced to sell the truck from a lack of options, feeling unsafe driving the vehicle, a potentially monumental cost to repair the wire harness and engine modules (GM refused to cover them despite the vehicle being under bumper-to-bumper warrant) and zero support or attempts to repair the truck from General Motors. The wiring harness and all components in the vehicle are connected and in my case, the main symptom shown was Service SabiliTrak.

Over 3 months, my "perfect" Z71 with less than 21k miles had electrical issues with StabiliTrak in the DIC, a jerky transmission, the truck dying, 3 different dealership visits, no repairs done, the dealerships having the truck close to 2 months, no assistance from GM customer service, and was still covered by the bumper-to-bumper warranty.

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Full Story:
I just had to sell my 2019 Chevy Colorado Z71 with less than 21k miles, in pristine condition, because of Stabilitrak and this is my story. Last winter, my window motor began to act funny, not going up automatically, malfunctioning. I reconfigured the motor as directed by my local dealer which lasted maybe a month before acting wrong again. I took the truck in for service and to replace the motor in May 2022 at GMC dealership #1. They held the truck for a week to replace the window motor and do an oil change.

Approximately 3 weeks later, I was driving normally on the highway when my truck suddenly died without warning. In the DIC, the "Service Stabilitrak" message came on along with the “Traction Off” light and “Traction Control System (TCS)/StabiliTrak” light. At approximately 19,800 miles, the truck lost all power, its steering response, and slowed rapidly from 80mph. Luckily after a few seconds it was on and responsive, as if nothing had happened. I pulled over and restarted the truck. It operated well enough to get home but the transmission was jerky - especially in low gears - and overall felt sluggish, as if it had no energy to work. I used my OBD reader and got trouble code U0420 - Invalid Data Received from Power Steering Control Module. I immediately scheduled service at GMC dealership #1, informing them of the occurrence and the transmission issues. Later that day, I pulled into the service aisle where the advisor plugged in a basic engine and transmission OBD2 reader only. She advised there were no codes logged and to continue driving like normal. The GMC advisor said “[the truck] is fine” and communication codes like U0420 are nothing to be concerned about. I was told if it happens again to “just bring it in." I expressed my concern and the advisor continued to tell me it wasn’t something to be concerned over or have them take the vehicle in to inspect.

After this meeting, I was unhappy with the service, feeling GMC dealership #1 didn’t take the issue seriously or do a proper inspection of the truck after explaining my concerns over the truck dying on a major freeway traveling at high speeds. Not feeling secure with this answer and the overall safety of the truck, I immediately called Chevrolet dealership #2. After explaining the occurrence from the day before, they immediately requested I bring the truck in for inspection and explained how the Stabilitrak message can be a minor issue or something major and required a certified technician to look it over. Chevrolet dealership #2 held the truck for 5 days.

Chevrolet dealership #2 ran the DTC codes and pulled:
  • U0100 - Lost Communication with ECM/PCM
  • U0102 - Lost Communication with Transfer Case Control Module (TCCM)
  • U0420 - Invalid Data Received from Power Steering Control Module
  • U0422 - Invalid Data Received from Body Control Module
Also listed in the report and warranty repairs was a replaced battery. Per Chevrolet dealership #2, after inspection the technician found “physical damage to battery…[and] cracks around [the] negative battery post.” The dealership removed and replaced the battery, cleared the codes and test drove the vehicle, no other issues were found at this time as to why the Stabilitrak would be coming up.

Upon picking up the vehicle, I asked the advisor why the battery was cracked or to explain why the truck died. The service advisor said “it was the battery” and “sometimes the battery can cause lights and error codes.”

One week after picking my Colorado up, the “Service Stabilitrak” message was shown in the DIC and the “Traction Off” light and “Traction Control System (TCS)/StabiliTrak” were back on while again driving along the freeway. Thankfully, the truck did not lose power, rather only the transmission became jerky and the truck began to feel sluggish. The lights and error message were on for a few seconds before turning off. Approximately 30 seconds later, they were on again - same symptoms - before turning off for the remainder of the drive home. This time, the truck was at ~20,100 miles and when the lights were on, I took pictures and videos of the instance.

The following morning, I texted Chevrolet dealership #2 asking what to do and requested to speak to the technician to see what they saw when the battery was replaced and what to watch out for before I could bring the truck in for service as the earliest availability was almost a week out. The service advisor told me I would not be able to speak to the technician, only them. She advised the truck would need to duplicate the issue(s) and they would need to perform different tests on the vehicle but until it duplicated, nothing would be done.

I understood the testing and duplicating the issue, but every GM dealership I have taken my truck to, the technicians have always talked to me if requested. I have some automotive background as does my partner who often accompanies me and having insight directly from the tech working on my truck shows transparency and a honest business. The lack of transparency was unacceptable and so I began to look for another dealership for help.

That day, I scheduled an appointment with Chevrolet dealership #3 than used two different OBD2 readers. One pulled two DTC codes:
  • B3205 - LF/Driver Window Motor Circuit Malfunction
  • U0420 - Invalid Data Received From Power Steering Control Module
The second OBD2 code reader scanned 24 different DTC codes (in total 30 codes with duplicates). While some were invalid, the found codes were:
  • P090F - ISO/SAE Reserved
  • P0007 - Fuel Shutoff Valve ‘A’ Control Circuit High
  • P0A09 - DC /DC Converter Status Circuit Low
  • P1600 - ECM/PCM Battery Malfunction
  • P0916 - Gear Shift Position Circuit Low
  • P000A - Intake ‘A’ Camshaft Position Slow Response Bank 1
  • P0D09 - Battery Charging System Positive Contractor Stuck Open
  • P1D00 - All CAN Malfunction Battery Condition Monitor Module - PCM
  • P075F - Transmission Fluid Level Too High
  • P20BA - Reductant Heater ‘A’ Control Circuit Performance
  • P000D - Exhaust ‘B’ Camshaft Position Slow Response
  • P0009 - Engine Position System Performance Bank 2
I did not drive the truck again until my appointment at Chevrolet dealership #3 where I dropped off the truck for 10 days. Photos, videos, and the growing list of DTC codes were provided to the service advisor. The dealership drove the truck 150+ miles trying to get the truck to recreate the intermittent problem. Per the Chevrolet dealership, GM and GM's engineering team TAC were contacted to determine the cause and potential remedies. After 10 days, the truck did not duplicate the issue and I was told to pick the truck up without any repairs. At this point, my bumper-to-bumper warranty was expiring in about 3 weeks.

While driving home, after ~30 miles, I stopped to fill the truck with a full tank of gas then continued the trip home. Randomly and with no warning, the gas indicator showed the fuel level was on empty, causing the dash light to blink and the indicator noise to go off. The A/C began to blow hot air and the dash lights for “Traction Off,” “Traction Control System (TCS)/Stabilitrak” and “Check Engine” were on. In the DIC, it showed, “Fuel Level Low,” “Steering Assist is Reduced Drive with Care,” “Service Trailer Brake System” and “Service Stabilitrak.” The lights on the gear shifter (P/R/N/D) and DIC to show the gear turned off and the transmission was completely unresponsive. The key locked in the console and once the vehicle turned off, would only turn to “Off” or “Accessory Mode” but the key could not be removed. All electronic systems and cameras were unresponsive, however, the engine continued to fire until the vehicle was turned off.

I attempted to scan the vehicle with the code reader but it was unable to connect to the vehicle, saying the truck was “off.” I tried calling OnStar to run a diagnostic report and request a tow back to Chevrolet dealership #3. OnStar was unable to connect to the vehicle, however I was able to schedule a tow. The battery was unplugged in an attempt to restart the systems but proved unsuccessful. Videos and pictures were taken to show.

The following morning the truck was towed back to Chevrolet dealership #3. They informed me the bumper-to-bumper warranty was expiring in 2 weeks and to contact the GM customer service while they looked my truck over. I provided the videos, pictures, and a list of trouble codes to the advisor and immediately opened a case with GM’s customer service where Joe* was assigned to my case.

After holding the truck for 3 days and looking it over for a few hours, the dealership called saying the system reset itself, the truck was working properly / no codes, and to come pick it up. Immediately after getting the keys, I scanned the vehicle with an OBD2 reader and 7 present codes with 3 history codes were shown.
  • U0100 - Lost Communication With ECM/PCM “A”
  • U0073 - Control Module Communication Bus “A” Off
  • U0101 - Lost Communication with TCM
  • B3205 - LF/Driver Window Motor Circuit Malfunction
  • U0100 - Lost Communication With ECM/PCM “A”
  • U0101 - Lost Communication with TCM
  • U0100 - Lost Communication With ECM/PCM “A”
  • B0010 - HISTORY - Passenger Frontal Stage 1 Deployment Control
  • U0100 - HISTORY - Lost Communication With ECM/PCM “A”
  • U0101 - HISTORY - Lost Communication with TCM
I immediately called the Service Director for Chevrolet dealership #3 who came out and tried to plug in his code reader which was now unable to connect to the vehicle. He took the truck to the back and used the GM reader. He came back with the keys to a loaner telling me the AC started blowing hot and multiple trouble codes were shown - they were not documented in my paperwork despite being requested. Following this, I discussed the potential causes for Stabilitrak and the more frequent reoccurring issues with the Service Director and Advisor. One theory (seen on another 2019 truck in the shop) was a faulty wire in the wire harness that travels from the negative post on the battery, through the power steering, and connects the different modules within the engine bay. Periodically the vehicle would “short-circuit” and cause module failures and damage to the systems. The Service Director mentioned how there was an increase in quality control issues on multiple vehicles produced during the 2019 GM strike (this was one) and the 2020 lockdowns. As a result, there were more warranty issues submitted related to the wire harness and electrical issues on vehicles.

During this time I was connecting weekly with my GM customer service rep Joe*. Joe initially described his role as in intermediate between myself and the dealership to ensure my vehicle was being repaired and I was satisfied with my GM service. After dropping the truck off a second time at Chevrolet dealership #3 and explaining the situation, Joe gave me my options - an OLC (Owner’s Loyalty Certificate), a component warranty for any components or modules replaced, or monthly payment assistance. He explained the OLC would entail creating a case to GM with the truck’s VIN, mileage, and options and GM would “buy” the vehicle and provide a credit to be used towards any purchase/lease of a new GM vehicle. In addition Joe advised I remain in constant contact with the dealership to ensure the vehicle was being repaired and to update him with any changes. During each call, Joe would emphasize the importance of GM loyalty (based on the number of previously owned GMs) and how this could significantly impact any case I may open with GM, or as he noted, would determine how seriously GM would take my case. He also noted how if I requested a manufacturer buy-back due to poor quality or manufacturer issues, he would build a case against GM on my behalf and present it to GM. However, GM rarely, if-ever, would approve a buy-back. Joe even provided an example where a man with a business who solely purchased GM trucks and was “loyal” requested a buy-back on a vehicle which GM declined.

In my case, I was not interested in the OLC - I was not pleased with GM and the Stabilitrak issues and would be required to purchase a new GM vehicle (at a higher price, with less options, and not set up how I wanted) and be forced to sell when I preferred not to. The component warranty was irrelevant as zero repairs had been done. The monthly payment assistance was a lot of documentation that needed to be provided, specific dates met, and would only be paid out once the vehicle was returned and all ROs closed. And the final buy-back option I was given was likely to not be approved as I wasn’t the preferred ”loyal” customer on paper to GM - I purchased this fully-loaded 2019 Colorado Z71 at 24 years old and have been loyal to GM, only took the truck to a certified GM dealer for regular maintenance, and had plans to purchase additional GM vehicles in the future. My purchase at 24, plans for additional GM vehicles, and countless GMs bought by family and friends did not suffice as “loyalty.” In GM’s perspective, I wasn’t “loyal” enough for a buy-back or proper repairs on my vehicle.

Chevrolet dealership #3 held the truck for over 2+ weeks, drove 150+ miles, disassembled the door and areas of the engine bay, and attempted to have the truck duplicate the problem. They reached out to GM for a resolution but GM kept requesting additional information, saying the pictures, videos, the log of 30+ trouble codes I recorded, the codes the dealership pulled, etc. were not enough to make any repairs.

I was told to come and pick up the truck. Again, no repairs were made. With the severity of the codes / issues, I had a family member in a follow vehicle should the vehicle have the same issue and all vehicle controls are lost causing a severe accident.

Chevrolet dealership #3 never provided a cause for the Stabilitrak issues and the car dying multiple times. Despite my constant phone calls and discussions with GM, no solution was provided for the faulty wiring and/or damaged modules on a 3 year old (under bumper-to-bumper warranty) vehicle. Instead, I was given excuses - GM employees explaining how the codes “don’t show anything” conclusive. How GM would not make repairs without proof collected on their system (they did get proof through codes of failed communication with the ECM and power steering however, this was not provided to me despite requesting the information). How the codes, photos, and videos I provided were insufficient evidence.

Joe called the next day, asking me how the dealership fixed the problem. I told him they didn’t, they drove the truck over 300 miles in total and held it for over a month, only to tell me GM refused to make any repairs despite reporting the truck was short-circuiting itself, the cracked battery and window motor were initial signs of a damaged wire harness and the symptoms with the transmission, power steering, BCM, ECM issues were happening because they are all on the same Stabilitrak System circuit.

Frustrated, I told Joe GM did not stand behind their bumper-to-bumper warranty because I took a vehicle in with the warranty and no repairs were made. Joe tried telling me GM would honor the bumper-to-bumper warranty because it was brought in before the warranty expired but only if it showed the exact same symptoms and was within some undisclosed amount of time (maybe less than six months but it was up to GM and the dealership to determine at that time - otherwise it would be out-of-pocket).

I explained that every time I provided proof to GM showing this intermittent problem but each time I was told it wasn’t enough documentation and when Chevrolet dealership #3 provided the proof, it still wasn't enough. I told Joe I was selling the truck and was unhappy with GM's lack of action. Explaining that the cost to replace the Power Steering module and ECM alone would cost me thousands (my bumper-to-bumper warranty just expired and GM would not cover it), plus the cost to repair the wire harness was exponential and GM refused to pay for the repair. After my experience, I will not buy another GM vehicle. Joe’s response to this statement was "GM is a big company and can take care of themselves" and losing my purchase and the purchase from those around me wouldn't impact GM, simply, the loss of my business was negligible.

I immediately sold the truck to Chevrolet dealership #4.

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I’m probably on the same trajectory. Multiple StabTrak warnings, none of the “cause” codes store. Turn off the truck and 3-5 minutes later restart with only CEL. After 3 start cycles everything back to normal. 2019 ExtCab Z71 and the issue began with less than 20K miles as well. Last one was driving on flat pavement and truck shuddered, then StabTrak warning and limp home mode (same result every time)

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Discussion Starter · #3 ·
I’m probably on the same trajectory. Multiple StabTrak warnings, none of the “cause” codes store. Turn off the truck and 3-5 minutes later restart with only CEL. After 3 start cycles everything back to normal. 2019 ExtCab Z71 and the issue began with less than 20K miles as well. Last one was driving on flat pavement and truck shuddered, then StabTrak warning and limp home mode (same result every time)
I’m sorry to hear that, it’s a real bummer when your truck starts to act up like that. Hope you’re able to get that fixed or resolved.
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