C1116 GMC Code - Manual Trailer Brake Apply Request Signal 1 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
- C1116 GMC indicates Manual Trailer Brake Apply Request Signal 1 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 C1116 GMC Description
What are the Possible Causes of the DTC C1116 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 C1116 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 C1116 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.
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Information for Specific GMC Models
- C1116 2014 GMC Sierra — Manual Trailer Brake Apply Request Signal 1 Malfunction
- C1116 2015 GMC Sierra — Manual Trailer Brake Apply Request Signal 1 Malfunction
- C1116 2016 GMC Sierra — Manual Trailer Brake Apply Request Signal 1 Malfunction
- C1116 2017 GMC Sierra — Manual Trailer Brake Apply Request Signal 1 Malfunction
- C1116 2018 GMC Sierra — Manual Trailer Brake Apply Request Signal 1 Malfunction
Frequently Asked Questions about C1116 GMC Code
1. What does the OBDII code C1116 mean for GMC vehicles?
Code C1116 indicates a malfunction in the Manual Trailer Brake Apply Request Signal 1 circuit, which is responsible for detecting trailer brake input from the manual brake control.
2. What are common symptoms of code C1116 in GMC vehicles?
Symptoms may include the trailer brakes not functioning correctly, a "Service Trailer Brake System" message on the dashboard, and reduced or no manual trailer brake control.
3. What causes the C1116 code to appear?
Common causes include faulty wiring or connections in the trailer brake control system, a failed trailer brake control module, or issues with the manual brake control lever.
4. Can a damaged trailer brake control module trigger code C1116?
Yes, a malfunctioning trailer brake control module is a common cause of this code, as it may fail to process the manual brake apply signal correctly.
5. How can I diagnose code C1116 in my GMC vehicle?
Start by inspecting the wiring and connectors related to the trailer brake control system for damage or corrosion, then test the manual brake control lever and trailer brake control module functionality.
6. Is it safe to drive with code C1116 active?
While it may be safe to drive without trailer brakes in some situations, towing a trailer without functional brakes can be dangerous and should be avoided until the issue is resolved.
7. Can code C1116 be fixed by replacing the manual brake control lever?
If the lever is faulty or not sending the correct signal to the trailer brake control module, replacing it may resolve the issue, but a full diagnosis is recommended first.
8. How much does it cost to repair code C1116 on a GMC vehicle?
Repair costs can vary depending on the root cause. Replacing the trailer brake control module may cost between $300 and $600, while fixing wiring issues might be less expensive.
9. Can a loose or corroded electrical connection cause the C1116 code?
Yes, poor electrical connections in the trailer brake system can disrupt the signal, leading to this code.
10. Do I need special tools to fix code C1116 on my GMC vehicle?
Diagnosing and repairing this code may require an OBDII scanner, a multimeter for testing circuits, and basic tools for inspecting and repairing wiring or replacing components.
Discuss the causes and fixes for C1116 GMC OBDII Code
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