THIS PRELIMINARY INFORMATION COMMUNICATION ADVISES THE TECHNICIAN THAT THE PART RESTRICTION FOR THE ACCESSORY DC POWER CONTROL MODULE AND THE SEAL KIT HAS ENDED.
full bulletin at NHTSA ↗2012 GMC Sierra electrical problems
severe 7 complaints filed with NHTSA · avg repair $850 · see electrical across all vehicles →
When does it fail?
Of the 7 electrical complaints filed for the 2012 GMC Sierra, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 mi.
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
No new NHTSA electrical complaint has been filed on this vehicle in over 10 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering electrical on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Preliminary Information communication provides the technician with the additional steps that are needed to help perform a successful brake bleed on the 2-Mode Hybrid with Regular Production Option Code HP2. With a battery maintainer installed on the vehicle use brake pressure bleeder that maintains 30 psi for the entire bleed procedure.
full bulletin at NHTSA ↗CADILLAC/CHEVROLET/GMC: ON SOME VEHICLES AND/OR TRUCKS, INSTRUMENT CLUSTER WILL ILLUMINATE, AFTER AN OIL CHANGE, INDICATING LOW OIL PRESSURE AND/OR SES LAMP WILL ILLUMINATE. MODEL 2007-13 CANYON, SIERRA, SAVANA, YUKON, CTS-V, ESCALADE, AVALANCHE, CAMARO SS, COLORADO, CORVETTE, EXPRESS, SILVERADO, SUBURBAN, TAHOE.
full bulletin at NHTSA ↗This technical bulletin provides repair information for repairing the IP to body harness connector to correct a customer concern for intermittent Malfunction Indicator Lamp (MIL) illuminated with Reduced Engine Power displayed and DTC P2138 set.
full bulletin at NHTSA ↗This Preliminary Information communication provides information to the technician about vehicle that may have an OnStar system that has progression tones when pressing the blue or red button. Technician will need to call General Motors Technical Assistance Center with the scan tool data from the OnStar system.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 4 most recent
Tl* the contact owns a 2012 GMC sierra. The contact stated that the vehicle experienced a loss of power which resulted in a front end collision with a guardrail. When the failure occurred, all the warning indicators illuminated. The vehicle was able to be operated after the crash. The vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. A police report was filed.…
Vehicle was taken to GMC dealer for headlight defect and we were informed that they would have to order parts. Drove truck back to site and while truck was running but stationary smoke was observed coming from the engine compartment. When the hood was raised the entire truck became engulfed and completely burned. *tr
Odometer Fraud. The contact purchased a 2012 GMC Sierra 1500. The contact stated that it was discovered that there was a mileage discrepancy. The vehicle was a private sale. At the time of purchase, the mileage was 111,000, and at the time of registration, it was discovered that the mileage was 243,000. The Carfax Report indicated that the vehicle was serviced at 149,000 and 179,000 miles, then…
While moving with transmission in drive, the ignition switch can be switched off. By doing so, the power steering and brakes fail to function properly. The steering wheel will lock, not allowing to steer. There have been a safety concerns with other gm products, why not this model? This is a safety concern.
Common questions
How serious is the electrical problem on the 2012 GMC Sierra?
It's a meaningful issue. 7 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Based on the 7 complaints filed, electrical issues most often appear around 59,581 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.