C1114 on Chevrolet: How to Diagnose & Fix
Manufacturer-Specific Chassis Control Code
1 Chevrolet model · 1 documented issue · 1 critical
C1114 on Chevrolet by model: symptoms, diagnosis and fix
On 2023 Tahoe models equipped with Integrated Trailer Brake Control, GM documented a distinct C1114 failure that has nothing to do with corroded wiring and everything to do with how the trailer's own battery interacts with the truck's electrical system. Service Bulletin 23-NA-149 describes the condition: when the customer's trailer carries its own battery that is kept topped up by a solar panel charger or a generator, that battery can become fully charged and end up at a higher state of charge than the Tahoe's own battery. Because the 7-way connector ties the two systems together, the higher-charge trailer battery back-feeds current into the trailer brake power control module and causes it to shut down. The result is a 'Check Trailer Wiring' message in the Driver Information Center, trailer brakes disabled, and DTC C1114 stored during diagnosis. GM notes the trigger points precisely: on internal-combustion vehicles it typically occurs during vehicle start-up or during a stop/start event; on EVs, when the vehicle is placed in propulsion. What makes this pattern maddening for owners is that it is intermittent and self-clearing — GM explicitly states the condition can persist until the vehicle's charging system brings the vehicle battery up to a higher state of charge, after which the message should go away and the trailer brakes work as normal. So the truck often arrives at the dealer with no active fault and a clean self-test. Owners of travel trailers, toy haulers, and off-grid or overland trailers with solar arrays report exactly this: brakes drop out shortly after a cold start or at a fuel stop, come back a few miles later, and repeat on the next trip. Because the trailer brakes are genuinely disabled while the fault is latched, this is a real safety exposure on grades and in panic stops, not merely a nuisance message. The same condition is documented across the platform — Suburban, Yukon, Escalade, Colorado, Canyon, Silverado 4500/5500 and the 2024 HD and EV trucks — with different service part numbers per family. The bulletin carries a production build-date breakpoint of January 21, 2024.
Common Symptoms
- 'Check Trailer Wiring' message in the Driver Information Center while towing
- Trailer brakes disabled with no braking assist from the trailer
- Fault appears at vehicle start-up or during a stop/start event
- Message clears itself after driving as the vehicle battery charges
- Only occurs with a trailer that has its own battery, solar charger, or generator
- DTC C1114 found stored during diagnosis
How to Fix
Confirm the pattern before ordering parts, because the symptom overlaps with ordinary trailer wiring faults. Two clues point at this bulletin rather than a wiring problem: the trailer has its own battery with a solar charger or generator, and the message appears at start-up or during a stop/start event rather than while braking. As an interim field check, disconnect the trailer's battery charging source or the 12-volt auxiliary pin at the 7-way and see whether the fault stops recurring — if it does, the back-feed path is confirmed. Note that GM says the condition can also clear itself once the vehicle's charging system brings the vehicle battery to a higher state of charge, so a single self-clearing event does not rule the bulletin out. The corrective action GM specifies in 23-NA-149 is not a wiring repair: replace the trailer brake control module with the updated part. For Tahoe, Suburban, Escalade and Yukon the service part number is 84857588 (Silverado HD/Sierra HD, Colorado/Canyon, HUMMER EV and Silverado EV use 23306694; Silverado 4500/5500 uses 23337305). Labor operation 2210300, Trailer Brake Control Module Replacement, uses published labor time. On a 2023 Tahoe still inside the 3-year/36,000-mile bumper-to-bumper coverage this should be a no-charge warranty repair, so raise the bulletin number with the dealer by name rather than accepting a diagnostic charge for 'trailer wiring.' Out of warranty, budget roughly $250-$450 for the module plus $120-$250 in labor and programming; the replacement module is installed per the Trailer Brake Control Module Replacement procedure in SI, so this is not a straight plug-and-play swap for a home mechanic. Before authorizing module replacement on a trailer without its own battery, work GM's PIT5509-series diagnostic first — on those vehicles C1114 is far more likely to be a poor trailer ground or corroded 7-way connector, and a new module will not fix it.
Sources for this issue (2)
- GM Service Bulletin 23-NA-149 (June 2024, version 4) — Check Trailer Wiring Message Displayed, Trailer Brake Disabled, and/or DTC C1114 Stored when Pulling Trailer with a Battery Generator or Solar Chargertsb
- GM Preliminary Information PIT5509J — Diagnostic Tip: Check and/or Service Trailer Brake System message DTC C1114 (2015-2024 Tahoe with ITBC RPO JL1)tsb
C1114 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C1114 mean on a Chevrolet?
C1114 stands for "Manufacturer-Specific Chassis Control Code." C1114 is a manufacturer-specific chassis trouble code, and its meaning differs between makers (for example, some applications associate it with a trailer brake control or other chassis control circuit). Broadly, it indicates that a chassis control module detected a fault in a circuit or component it monitors. Because there is no single generic definition, do not assume a specific component without confirmation. Use a capable scan tool with manufacturer data or the factory service manual to determine what C1114 means on your exact vehicle. On Chevrolet it is documented across 1 model: Tahoe.
What are the most common causes of C1114?
The most common causes of C1114 are: Wiring or connector fault in the affected circuit, Faulty control solenoid or actuator, Open or short circuit (to ground or power), Low or unstable supply voltage / poor ground, Internal control module fault, Corrosion or moisture at connectors. The specific cause varies by vehicle.
How much does it cost to fix C1114 on a Chevrolet?
Repair costs vary widely with the root cause and Chevrolet model; each issue on this page carries its own estimate where one is published.
Looking for C1114 on a different make?
View C1114 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.