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C111B Cadillac Code - Trailer Brake Power Control Module System Voltage

Quick Answer

The Chassis Control Module-Auxiliary receives inputs from the Trailer Brake Power Control Module; these inputs are used to determine trailer connection and the amount of voltage supplied to the trailer brakes. Common causes include Faulty Trailer Brake Power Control Module, Trailer Brake Power Control Module harness is open or shorted, Trailer Brake Power Control Module 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: C111B Cadillac indicates Trailer Brake Power Control Module System Voltage.
Common causes: Common causes include Faulty Trailer Brake Power Control Module, Trailer Brake Power Control Module harness is open or shorted, Trailer Brake Power Control Module 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.

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Code Popularity 1,040

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 17, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C111B Cadillac Description

The Chassis Control Module-Auxiliary receives inputs from the Trailer Brake Power Control Module; these inputs are used to determine trailer connection and the amount of voltage supplied to the trailer brakes. The Diagnostic Trouble Code (DTC) will be set when the Trailer Brake Power Control Module detects a short to ground, open, a short to voltage, or a plausibility failure on the trailer brake output circuit.

OBDII Code C111B Cadillac - Trailer Brake Power Control Module System Voltage - AutoCodes.com — C111B Cadillac Code - Trailer Brake Power Control Module System Voltage

What does this mean?

What are the Possible Causes of the DTC C111B Cadillac?

Faulty Trailer Brake Power Control Module
Trailer Brake Power Control Module harness is open or shorted
Trailer Brake Power Control Module circuit poor electrical connection
Faulty Chassis Control Module-Auxiliary

How to Fix the DTC C111B Cadillac?

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 does this mean?

Code Tech Notes

C111B:03 Trailer Brake Power Control Module System Voltage Below Threshold
C111B:07 Trailer Brake Power Control Module System Voltage Above Threshold
C111B:5A Trailer Brake Power Control Module System Voltage Plausibility Failure

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C111B Cadillac 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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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about C111B Cadillac Code

1. What does the OBDII code C111B mean on a Cadillac?

C111B indicates an issue with the Trailer Brake Power Control Module system voltage, suggesting the module is detecting an incorrect or unstable voltage.

2. What are common symptoms of the C111B code on a Cadillac?

Symptoms may include the trailer brake system not functioning, a warning light on the dashboard, or a message indicating a trailer brake system fault.

3. What causes the C111B code to appear on a Cadillac?

Common causes include a weak or failing battery, poor electrical connections, a faulty Trailer Brake Power Control Module, or issues with the module's wiring harness.

4. How does the C111B code affect trailer braking?

The code may result in the trailer brake system failing to activate, reducing braking performance when towing a trailer.

5. Can a low vehicle battery trigger the C111B code?

Yes, a low or unstable vehicle battery can cause voltage issues, triggering the C111B code.

6. How do you diagnose the C111B code on a Cadillac?

Diagnosis involves checking the vehicle's battery and charging system, inspecting the Trailer Brake Power Control Module and its wiring, and verifying proper ground connections.

7. Is it safe to drive with the C111B code active?

Driving may be safe without a trailer, but towing with a malfunctioning trailer brake system can be hazardous and should be avoided until the issue is resolved.

8. How is the C111B code typically repaired on a Cadillac?

Repairs may include replacing the battery, repairing or replacing damaged wiring, cleaning or tightening electrical connections, or replacing the Trailer Brake Power Control Module.

9. Can a software issue cause the C111B code?

Yes, in some cases, outdated or corrupted software in the control module may cause the code, requiring a software update from a dealership.

10. What tools do I need to troubleshoot the C111B code?

You'll need a multimeter to check voltage and continuity, a scan tool with OBDII capabilities to read and clear codes, and possibly a service manual for wiring diagrams.