C1118 GMC Code - Trailer Brake Control Sensitivity Switch Circuit Malfunction
Quick Answer
The trailer brake control system has a control panel with the trailer gain and manual apply switches. Common causes include Faulty Trailer Brake Control Switch, Trailer Brake Control Switch harness is open or shorted, Trailer Brake Control Switch circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- C1118 GMC indicates Trailer Brake Control Sensitivity Switch Circuit Malfunction.
- Common causes
- Common causes include Faulty Trailer Brake Control Switch, Trailer Brake Control Switch harness is open or shorted, Trailer Brake Control Switch circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code C1118 GMC Description
What are the Possible Causes of the DTC C1118 GMC?
- Faulty Trailer Brake Control Switch
- Trailer Brake Control Switch harness is open or shorted
- Trailer Brake Control Switch circuit poor electrical connection
- Faulty Chassis Control Module-Auxiliary
How to Fix the DTC C1118 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the C1118 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the C1118 GMC code?
Need more information on how to fix the C1118 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the C1118 GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- C1118 2014 GMC Sierra — Trailer Brake Control Sensitivity Switch Circuit Malfunction
- C1118 2015 GMC Sierra — Trailer Brake Control Sensitivity Switch Circuit Malfunction
- C1118 2016 GMC Sierra — Trailer Brake Control Sensitivity Switch Circuit Malfunction
- C1118 2017 GMC Sierra — Trailer Brake Control Sensitivity Switch Circuit Malfunction
- C1118 2018 GMC Sierra — Trailer Brake Control Sensitivity Switch Circuit Malfunction
Frequently Asked Questions about C1118 GMC Code
1. What are the common symptoms of OBDII code C1118 GMC (Trailer Brake Control Sensitivity Switch Circuit Malfunction)?
The common symptoms include issues with the trailer brake system, such as erratic braking, non-responsive brakes, or the trailer brakes engaging unexpectedly.
2. What can cause the OBDII code C1118 GMC to trigger?
This code is typically triggered by a malfunction in the sensitivity switch circuit of the trailer brake control system. It can be caused by wiring issues, a faulty sensitivity switch, or problems with the trailer brake control module.
3. How can I diagnose the cause of OBDII code C1118 GMC?
Diagnosing this code involves checking the wiring connections, testing the sensitivity switch for proper functioning, and using a scan tool to communicate with the trailer brake control module for any stored codes or data.
4. Are there any repair tips for fixing OBDII code C1118 GMC?
Repairing this code may involve repairing or replacing damaged wiring, replacing the sensitivity switch, or reprogramming the trailer brake control module. It's essential to follow manufacturer-specific repair procedures for proper troubleshooting and repair.
5. Can I still drive my vehicle with OBDII code C1118 GMC present?
It is not recommended to drive the vehicle with this code present, especially if it affects the trailer brake system. Addressing the issue promptly is crucial for the safety and proper functioning of the trailer brakes.
6. How serious is OBDII code C1118 GMC?
While this code may not affect the drivability of the vehicle itself, it can impact the functionality of the trailer brake system, which is crucial for towing safety. It should be addressed promptly to avoid any potential safety hazards.
7. Can I reset OBDII code C1118 GMC with a simple reset tool?
While you may be able to clear the code temporarily with a reset tool, it is essential to diagnose and repair the underlying issue causing the code to prevent it from reoccurring.
8. How much does it typically cost to repair OBDII code C1118 GMC?
The cost of repairing this code can vary depending on the cause of the issue, the labor rates in your area, and the specific parts needed for the repair. It's recommended to obtain quotes from automotive professionals for an accurate estimate.
9. Is OBDII code C1118 GMC specific to certain GMC models?
This code is specific to GMC vehicles equipped with a trailer brake control system. It may be found in various GMC models that have this feature installed.
10. Can I prevent OBDII code C1118 GMC from occurring in the future?
Regular maintenance of the trailer brake system, including checking the wiring connections and ensuring proper functioning of the sensitivity switch, can help prevent this code from occurring in the future.
Discuss the causes and fixes for C1118 GMC OBDII Code
Code C1118 GMC comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
