AutoCodes – Generic – C120C

C120C Code - Brake Pedal Position Sensor 4 Not Plausible

Quick Answer

The Electronic Brake Control Module (EBCM) uses inputs from the electronic brake control brake pedal position sensor to determine when the brake is applied and how much force is used. Common causes include Faulty Brake Pedal Position Sensor, Brake Pedal Position Sensor harness is open or shorted, Brake Pedal Position Sensor 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: C120C indicates Brake Pedal Position Sensor 4 Not Plausible.
Common causes: Common causes include Faulty Brake Pedal Position Sensor, Brake Pedal Position Sensor harness is open or shorted, Brake Pedal Position Sensor 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,486

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 Jun 18, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code C120C Description

The Electronic Brake Control Module (EBCM) uses inputs from the electronic brake control brake pedal position sensor to determine when the brake is applied and how much force is used. The electronic brake control module monitors when the driver's foot is on the brake and locks the offset. The offset is locked when 3 out of the 4 inputs indicate the brake pedal is applied. The 4 inputs are brake pedal travel 1, brake pedal travel 2, master cylinder pressure sensor, and the brake pedal position sensor. These inputs are used to determine the driver's braking intent which is used to the control amount of pressure applied to the wheels.

OBDII Code C120C - Brake Pedal Position Sensor 4 Not Plausible - AutoCodes.com — C120C Code - Brake Pedal Position Sensor 4 Not Plausible

What does this mean?

What are the Possible Causes of the DTC C120C?

Faulty Brake Pedal Position Sensor
Brake Pedal Position Sensor harness is open or shorted
Brake Pedal Position Sensor circuit poor electrical connection
Faulty Electronic Brake Control Module (EBCM)

How to Fix the DTC C120C?

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 C120C 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 C120C code?

Need more information on how to fix the C120C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C120C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C120C Buick — Brake Pedal Position Sensor 4 Not Plausible
C120C Cadillac — Brake Pedal Position Sensor 4 Not Plausible
C120C Chevrolet — Brake Pedal Position Sensor 4 Not Plausible
C120C GMC — Brake Pedal Position Sensor 4 Not Plausible
C120C Lexus — Linear Solenoid Power Supply System Malfunction
C120C Mitsubishi — Abnormality In FR/RL Wheel Suction Valve System
C120C Toyota — Linear Solenoid Power Supply System Malfunction

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 C120C Code

What does the OBDII code C120C mean?

C120C indicates that the brake pedal position sensor 4 is sending signals to the vehicle's computer that are not consistent with expected values, suggesting a malfunction.

What are the common symptoms of a C120C code?

Common symptoms include warning lights on the dashboard, issues with the brake system, erratic braking behavior, and potential loss of cruise control functionality.

What could cause the C120C code to trigger?

Potential causes include a faulty brake pedal position sensor, wiring issues, poor electrical connections, or problems with the vehicle's braking system.

How can I diagnose the C120C code?

To diagnose the C120C code, use an OBDII scanner to confirm the code, inspect the brake pedal position sensor and wiring for damage, and check for any related codes that could indicate other issues.

What are some common repair solutions for the C120C code?

Common repairs include replacing the brake pedal position sensor, repairing or replacing damaged wiring or connectors, and ensuring proper calibration of the brake system.

Can I drive my vehicle if the C120C code is present?

While it may be possible to drive the vehicle, it is not recommended due to potential braking issues. It's best to address the code promptly to ensure safe operation.

What tools do I need to fix the C120C code?

You will typically need an OBDII scanner, multimeter for electrical testing, basic hand tools for sensor replacement, and possibly a repair manual for your specific vehicle.

Will clearing the C120C code fix the problem?

Clearing the code may temporarily turn off the warning light, but it will not fix the underlying issue. A proper diagnosis and repair are necessary to prevent the code from reappearing.

How much does it typically cost to repair the C120C code?

Repair costs can vary widely depending on the cause, but sensor replacement may range from $100 to $300, while more extensive electrical repairs could be higher. It's best to get a quote from a professional mechanic.