GM has issued a customer satisfaction program for certain units of the 2023 GMC Sierra 1500 which were seemingly produced with an incorrect wiring harness installed. The incorrect wiring harness was also fitted to some units of the 2023 Chevy Silverado 1500.
Problems associated with the incorrect wiring harness include missing circuits needed to power specific features or pieces of equipment, which vary according to the trim level of the pickup and its options.
Very few 2023 GMC Sierra trucks in total were affected with incorrectly installed wiring harnesses. GM’s service bulletin lists the VIN numbers of three GMC Sierras in all, plus a trio of 2023 Chevy Silverado pickups similarly affected, giving a total of six vehicles for both nameplates.
GM instructs its dealerships to inspect 2023 GMC Sierra trucks which are suspected to be affected by the incorrect wiring harness installation prior to ordering parts. The dealer should order a suitable service cable kit from the Warranty Parts Center if the truck is in fact fitted with the wrong body harness for its trim level and equipment.
The replacement program launches in March 2023 and continues through April 30th, 2025. The replacement harness is VIN specific, and the parts request must also be VIN specific to each individual vehicle.
The process of incorrect harness removal and subsequent correct harness installation takes about four hours of labor per GM estimates. The replacement is to be carried out free of charge to the customer.
Affected 2023 GMC Sierra 1500 owners who have questions about the replacement can call GMC’s customer service number, referencing the GM customer satisfaction program number below.
- GM Customer Satisfaction Program Number: N222391510
- GMC Customer Service: 1-800-462-8782
As a reminder, the 2023 GMC Sierra 1500 can be ordered with a variety of engine options. The base powerplant is the turbocharged 2.7L I4 L3B gasoline engine, rated at 310 horsepower and 430 pound-feet of torque. This is followed by the atmospheric 5.3L V8 L84 gasoline engine developing 355 horsepower and 383 pound-feet of torque, and the atmospheric 6.2L V8 L87 gasoline engine developing 420 horsepower and 460 pound-feet of torque.
The GMC Sierra 1500 has a single diesel engine option, the new-for-2023 3.0L I6 LZ0 turbodiesel, which produces 305 horsepower and 495 pound-feet of torque. The LZ0 is the “second iteration” of GM’s 3.0L Duramax and is the replacement for the outgoing 3.0L I6 LM2 turbodiesel.
As for transmission options, the L3B engine is offered with the GM eight-speed automatic, while the L84, the L87 and the LZ0 powerplants are paired with the GM 10-speed automatic.