AutoCodes – Generic – P25C9

P25C9 Code - Brake System Control Module 2 Requested MIL Illumination

Quick Answer

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. Common causes include Check Brake System Control Module for codes, Faulty Brake System Control Module. 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: P25C9 indicates Brake System Control Module 2 Requested MIL Illumination.
Common causes: Common causes include Check Brake System Control Module for codes, Faulty Brake System Control Module.
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 756

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 15, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P25C9 Description

Control modules constantly monitor the vehicle for any condition which may adversely affect vehicle performance. If a condition is detected, the module sets a Diagnostic Trouble Code (DTC) and sends a serial data message to the Engine Control Module (ECM). The ECM sets a DTC to inform that the module has set a DTC. The serial data message sent by the module also contains a request for the ECM to illuminate the Malfunction Indicator Lamp (MIL).
The DTC will be set when the ECM receives a serial data message from the Brake System Control Module indicating that DTC has been set in the module.

OBDII Code P25C9 - Brake System Control Module 2 Requested MIL Illumination - AutoCodes.com — P25C9 Code - Brake System Control Module 2 Requested MIL Illumination

What does this mean?

What are the Possible Causes of the DTC P25C9?

Check Brake System Control Module for codes
Faulty Brake System Control Module

How to Fix the DTC P25C9?

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 P25C9 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 P25C9 code?

Need more information on how to fix the P25C9 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P25C9 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P25C9 Buick — Brake System Control Module 2 Requested MIL Illumination
P25C9 Cadillac — Brake System Control Module 2 Requested MIL Illumination
P25C9 Chevrolet — Brake System Control Module 2 Requested MIL Illumination
P25C9 GMC — Brake System Control Module 2 Requested MIL Illumination

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 P25C9 Code

1. What does the OBDII code P25C9 mean?

P25C9 indicates that the Brake System Control Module 2 has requested the malfunction indicator light (MIL) to illuminate due to a detected issue within the brake system.

2. What are the common symptoms of code P25C9?

Symptoms may include the MIL or brake warning light turning on, reduced braking performance, ABS system malfunction, or loss of traction control functionality.

3. What causes the P25C9 code to appear?

Common causes include a faulty Brake System Control Module 2, wiring issues, communication errors in the CAN bus network, or low brake fluid levels.

4. Can I still drive my vehicle with the P25C9 code?

While the car may still be drivable, it is not recommended as braking performance could be compromised, increasing the risk of an accident.

5. How is the P25C9 code diagnosed?

A technician will use a diagnostic scanner to read the code, inspect the brake system, check wiring and connections, and test the Brake System Control Module 2 for faults.

6. What repairs are needed to fix code P25C9?

Repairs may include replacing the Brake System Control Module 2, fixing damaged wiring or connectors, updating module software, or addressing brake fluid issues.

7. Is the P25C9 code related to the ABS system?

Yes, it often relates to the ABS or traction control systems since these functions are integrated with the Brake System Control Module.

8. Can resetting the MIL clear the P25C9 code permanently?

Resetting the MIL may temporarily clear the code, but the underlying issue must be fixed to prevent the code from returning.

9. How much does it cost to repair a P25C9 code?

Repair costs vary widely depending on the root cause but can range from $100 for minor wiring repairs to over $1,000 for Brake System Control Module replacement.

10. What tools are needed to troubleshoot the P25C9 code?

A professional-grade OBDII scanner, multimeter, and wiring diagrams are essential for diagnosing and fixing issues related to this code.