Some 2024-2026 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks may have several communication issues and CAN Bus errors as well as multiple illuminated warning MILs and messages on the Driver Information Center while the vehicle is running/driving/idling. The vehicle also may lose communication with the Electronic Brake Control Module. Several DTCs may be set, including DTC B1980 (No Environment Identifier Received From Brake System Control Module 1) and communication DTCs U1610, U0121, U2418, U2419, U160F, U0101, U0131, U1611 and U0401.
These conditions may be caused by high resistance to ground on grounds G103A and G103B of the body wiring harness. These grounds are located under the hood on the inboard side of the left body structure of the HD trucks, next to the X50A Engine Wiring Harness Junction Block. (Fig. 16)
Fig. 16
Clean the mating surface on the body structure for these grounds and confirm proper system operation. (Fig. 17)
Fig. 17
Refer to Bulletin #26-NA-202 for more information.
– Thanks to Kevin Minor
