AutoCodes – GMC – C12B2 GMC

C12B2 GMC Code - ABS Master Cylinder Pressure Sensor Circuit Open or Short To Ground

Quick Answer

The Electronic Brake Control Module (EBCM) uses input from the master cylinder pressure sensor for more accurate control during a vehicle stability enhancement system event. Common causes include Faulty Brake Pressure Modulator, Brake Pressure Modulator harness is open or shorted, Brake Pressure Modulator 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: C12B2 GMC indicates ABS Master Cylinder Pressure Sensor Circuit Open or Short To Ground.
Common causes: Common causes include Faulty Brake Pressure Modulator, Brake Pressure Modulator harness is open or shorted, Brake Pressure Modulator 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 902

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 Sep 04, 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 C12B2 GMC Description

The Electronic Brake Control Module (EBCM) uses input from the master cylinder pressure sensor for more accurate control during a vehicle stability enhancement system event. The master cylinder pressure sensor is internal to the brake pressure modulator.

OBDII Code C12B2 GMC - ABS Master Cylinder Pressure Sensor Circuit Open or Short To Ground - AutoCodes.com — C12B2 GMC Code - ABS Master Cylinder Pressure Sensor Circuit Open or Short To Ground

What does this mean?

What are the Possible Causes of the DTC C12B2 GMC?

Faulty Brake Pressure Modulator
Brake Pressure Modulator harness is open or shorted
Brake Pressure Modulator circuit poor electrical connection

How to Fix the DTC C12B2 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 C12B2 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 C12B2 GMC code?

Need more information on how to fix the C12B2 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C12B2 GMC code diagnosed by a professional: Find a repair shop in your area

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 C12B2 GMC Code

1. What are the common symptoms of OBDII code C12B2 GMC?

The common symptoms of this code may include the ABS warning light illuminating on the dashboard, issues with the ABS system functionality, and potential loss of brake assist.

2. What does the OBDII code C12B2 GMC indicate?

The code C12B2 indicates a potential problem with the ABS master cylinder pressure sensor circuit being open or short to ground in a GMC vehicle.

3. What are the possible causes of OBDII code C12B2 GMC?

Possible causes of this code include a faulty ABS master cylinder pressure sensor, damaged wiring or connectors in the sensor circuit, or an issue with the ABS control module.

4. How can I diagnose the ABS master cylinder pressure sensor circuit issue?

Diagnosing the ABS master cylinder pressure sensor circuit issue may involve using a diagnostic scan tool to read the trouble code, inspecting the sensor and its wiring for visible damage, and performing circuit tests to check for continuity.

5. Can I still drive my GMC vehicle with the ABS code C12B2 present?

It is not recommended to drive the vehicle with an active ABS code, as it may affect the proper functioning of the ABS system and compromise safety during braking.

6. How can I repair the ABS master cylinder pressure sensor circuit issue?

Repairing the ABS master cylinder pressure sensor circuit issue may involve replacing the faulty sensor, repairing damaged wiring or connectors, or reprogramming the ABS control module.

7. Is it necessary to reset the OBDII code C12B2 after completing repairs?

Yes, it is recommended to clear the OBDII code C12B2 after completing repairs to reset the ABS system and ensure that the issue has been resolved.

8. Can a DIY enthusiast fix the ABS master cylinder pressure sensor circuit problem?

While some DIY enthusiasts may have the skills to diagnose and repair simple wiring issues, it is advisable to seek professional help for more complex ABS system problems like the C12B2 code.

9. How much does it cost to fix the ABS master cylinder pressure sensor circuit issue?

The cost of fixing the ABS master cylinder pressure sensor circuit issue can vary depending on the extent of the problem, the parts needed for repair, and the labor rates of the repair shop.

10. How can I prevent OBDII code C12B2 GMC from occurring again in the future?

To prevent the recurrence of the C12B2 code, it is essential to perform regular maintenance on the ABS system, address any warning signs promptly, and ensure proper care of the ABS components in the vehicle.