C1115 2018 GMC Sierra Code - Manual Trailer Brake Apply Request Switch Signal
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
- C1115 2018 GMC Sierra indicates Manual Trailer Brake Apply Request Switch Signal.
- 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 C1115 2018 GMC Sierra Description
What are the Possible Causes of the DTC C1115 2018 GMC Sierra?
- 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 C1115 2018 GMC Sierra?
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.
Code Tech Notes
C1115:5A Manual Trailer Brake Apply Request Switch Signal Plausibility Failure
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the C1115 2018 GMC Sierra 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 C1115 2018 GMC Sierra code?
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Need Help with the Code?
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Frequently Asked Questions about C1115 2018 GMC Sierra Code
1. What does the OBDII code C1115 mean on a 2018 GMC Sierra?
The C1115 code indicates an issue with the Manual Trailer Brake Apply Request Switch Signal, which is part of the trailer brake control system.
2. What are the common symptoms of the C1115 code?
Symptoms may include the trailer brake system not functioning, a warning message on the dashboard, or a loss of manual trailer brake control.
3. What causes the C1115 code to appear?
Common causes include a faulty manual trailer brake switch, damaged wiring or connectors, or a malfunction in the trailer brake control module.
4. How do I diagnose the C1115 code?
Diagnosis involves inspecting the manual trailer brake switch, checking the wiring and connectors for damage, and using a scan tool to monitor the trailer brake signal.
5. Can I still drive my truck with the C1115 code?
Yes, you can drive the truck, but the trailer brake system may not function properly, which could impact towing safety.
6. How do I fix the C1115 code on my 2018 GMC Sierra?
Repairs may include replacing the manual trailer brake switch, repairing damaged wiring, or replacing the trailer brake control module if necessary.
7. How much does it cost to fix the C1115 code?
Repair costs vary but typically range from $100 to $300, depending on whether the issue is the switch, wiring, or module.
8. Can I reset the C1115 code without fixing the problem?
You can clear the code with a scan tool, but it will likely return unless the root cause is addressed.
9. Is the C1115 code a common issue on the 2018 GMC Sierra?
It’s not extremely common but can occur, especially in trucks frequently used for towing.
10. Do I need to reprogram the trailer brake control module after repairs?
In most cases, reprogramming is not required, but it’s recommended to check the owner’s manual or consult a professional.
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