The trailer brakes may become disabled while pulling a trailer on some 2023 Colorado, Tahoe, Suburban, Silverado 4500/5500, Canyon, Yukon, Escalade; 2024 Silverado 2500HD/3500HD, Silverado EV, Sierra 2500HD/3500HD and HUMMER EV models due to a trailer battery condition. (Fig. 12) DTC C1114 (Trailer Brake Control Solenoid Valves Control Circuit) may be set and a Service Trailer Brake System message may appear on the Driver Information Center.
Fig. 12
The trailer brakes may be disabled if the customer’s trailer has a solar panel battery charger or generator. If the trailer’s battery becomes fully charged and has a higher charge than the vehicle’s battery, it can feed back into the trailer brake control module, causing it to shut down.
Anytime the vehicle’s battery state of charge is lower than the trailer’s battery, this condition may occur. Once the vehicle’s charging system brings the vehicle’s battery up to a higher state of charge, the condition should no longer occur and the trailer brakes will work as normal.
If diagnosis shows the trailer brake is disabled, replace the trailer brake control module. (Fig. 13, Tahoe shown) An updated part is available. Refer to Trailer Brake Control Module Replacement in the appropriate Service Information.
Fig. 13
For additional information and part numbers, refer to Bulletin #23-NA-149.
– Thanks to Kevin Minor
