82 owner complaints to NHTSA about the 2020 GMC Sierra cite electrical system, 17% of all 495 complaints for this model year. NHTSA also lists 1 recall on this component.
“The contact owns a 2020 GMC Sierra 1500. The contact stated that the vehicle failed to start intermittently and needed to be jumpstarted. The vehicle was taken to the dealer, and it was determined that there was corrosion on the ground wire which caused the failure. The vehicle was not repaired because the vehicle was not included in Customer Satisfaction Program: N252515590 with NHTSA ID Number: 11027795 (Electrical System) for the ground wire replacement. The manufacturer was informed of the failure and confirmed that the vehicle was not covered. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 51,000.”
“6 months after owning it the lifters went bad got them Fixed then they immediately went bad again also bent rods then a day after getting that fixed again the oil pump went bad it was issue after issue”
“5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake manifold.”
“Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts with GM dealers repeatedly stating the issues were repaired and returning our vehicle to us. We began making the CEO and Executive team aware of the potentially deadly safety hazards including the fact that I, [XXX] am disabled and power wheelchair dependent requiring a truck that can carry my power wheelchair. We have sent numerous emails to Ms. [XXX] and the Executive team numerous times informing them in detail, each time, of all issues involved. We started communicating via phone and email with customer care to no avail. All attempts at repair finally ended in complete engine failure leaving us with an estimate to replace the engine of over $13,000. We have also, submitted a detailed complaint to the Attorney General’s Office and after review were given the Case # TCP - XXX. I will attach the Complaint and Addendum sent to the Attorney General along with two of…”
“- THE GROUND STRAP CORRODED AND BROKE APART. YES, I HAVE THE GROUND CABLE THAT FAILED, IF NEEDED FOR INSPECTION. - YES!!! THE TRUCK'S STEERING KEPT GOING IN AND OUT OF MANUAL STEERING AND THE ENGINE REDUCED IN SPEED ALLOWED, AND THEN THE ENGINE CUT OUT ON ME COMPLETELY - WHILE I WAS IN THE MIDDLE OF A BUSY ROAD TRYING TO TURN ONTO A SIDE STREET. THEN THE ENGINE WOULD NOT RESTART. - I HAD THE TRUCK TOWED ON A FLAT BED TO A GMC DEALERSHIP NEARBY. THEY CONFIRMED THE ISSUE WAS THAT THE GROUND STRAP FAILED. THEY REPLACED THE PART AT MY COST, WHICH FIXED THE ISSUES. - YES, THE DEALERSHIP INSPECTED AND CONFIRMED THE ISSUE WAS THE CORRODED AND BROKEN GROUND STRAP. - YES, THERE WERE MANY WARNING MESSAGES THAT STARTED TO APPEAR ABOUT 3-4 DAYS PRIOR TO THE COMPLETE FAILURE OF THE ELECTRICAL SYSTEM. I STARTED SEEING A MESSAGE ABOUT SERVICING THE TRAILER BRAKE SYSTEM, AND ANOTHER ABOUT SERVICING THE SIDE DETECTION SYSTEM. THEN A SERVICE POWER STEERING WARNING AND TO DRIVE WITH CARE. THE CHECK ENGINE LIGHT WAS OFF AND ON OVER THAT TIME. - I CHECKED THE WIRE CONNECTIONS IUNDER MY VEHICLE TO CHECK FOR BROKEN WIRES OR CORROSION. I DID NOT FIND ANY. I THEN CHECKED IF A HARD…”
“2020 GMC sierra 1500 infotainment system including navigation,OnStar and voice command, stoped working on Friday May 15th with no prior warning. These systems are integral for modern safe travel and severely affects the value and driver confidence in the vehicle. It seems to be running mechanically sound but, with some of the communications and information systems not working properly I am unsure how much of the info is incorrect like the clock (which can not be set manually). I have scheduled an appointment with the dealer for June 2nd the earliest date available.”
Showing 6 of 82 reports. Read every report on NHTSA.gov.
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks. The battery positive (B+) cable rings may have been manufactured with excessive glue, potentially causing an intermittent electrical connection between the B+ cable and alternator.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.