AutoCodes – Generic – U1408

U1408 Code - Implausible Brake Signal Received

Quick Answer

The Diagnostic Trouble Code (DTC) sets when the Body Control Module (BCM) receives an invalid signal from the Anti-lock Brake System (ABS) Module. Common causes include Faulty Anti-lock Brake System (ABS) Module, Anti-lock Brake System (ABS) Module harness is open or shorted, Anti-lock Brake System (ABS) 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: U1408 indicates Implausible Brake Signal Received.
Common causes: Common causes include Faulty Anti-lock Brake System (ABS) Module, Anti-lock Brake System (ABS) Module harness is open or shorted, Anti-lock Brake System (ABS) 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 16,465

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 May 17, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1408 Description

The Diagnostic Trouble Code (DTC) sets when the Body Control Module (BCM) receives an invalid signal from the Anti-lock Brake System (ABS) Module.

OBDII Code U1408 - Implausible Brake Signal Received - AutoCodes.com — U1408 Code - Implausible Brake Signal Received

What does this mean?

What are the Possible Causes of the DTC U1408?

Faulty Anti-lock Brake System (ABS) Module
Anti-lock Brake System (ABS) Module harness is open or shorted
Anti-lock Brake System (ABS) Module circuit poor electrical connection

How to Fix the DTC U1408?

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 U1408 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 U1408 code?

Need more information on how to fix the U1408 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1408 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1408 Chrysler — Implausible Brake Signal Received
U1408 Dodge — Implausible Brake Signal Received
U1408 Jeep — Implausible Brake Signal Received
U1408 RAM — Implausible Brake Signal Received

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 U1408 Code

1. What are the common symptoms of OBDII code U1408 (Implausible Brake Signal Received)?

- Common symptoms include malfunctioning brake lights, ABS warning light illuminated on the dashboard, and potential loss of communication with the brake system.

2. What are some possible causes of OBDII code U1408?

- Possible causes can include a faulty brake light switch, damaged wiring or connectors in the brake system circuit, or a problem with the ABS module.

3. How can I diagnose the issue related to OBDII code U1408?

- Diagnosis typically involves checking the brake light switch for proper operation, inspecting the wiring and connectors for any damage, and using a scan tool to communicate with the ABS module.

4. Can driving with OBDII code U1408 pose any risks?

- Driving with this code may lead to issues with brake light functionality and potentially affect the ABS system's performance, so it's advisable to address the problem promptly.

5. How can I repair OBDII code U1408?

- Repairing the code may involve replacing the brake light switch, repairing any damaged wiring or connectors, or recalibrating the ABS module to resolve the implausible brake signal issue.

6. Are there any DIY tips for troubleshooting OBDII code U1408?

- DIY troubleshooting tips include checking the brake light switch for proper adjustment, inspecting the brake system wiring for visible damage, and ensuring all connections are secure.

7. Can a mechanic help with diagnosing and repairing OBDII code U1408?

- Yes, a qualified mechanic can use advanced diagnostic tools to pinpoint the issue causing the implausible brake signal and perform the necessary repairs to resolve the code.

8. How long does it typically take to fix OBDII code U1408?

- The repair time can vary depending on the exact cause of the code and the complexity of the fix, but it usually takes a few hours to diagnose and repair the issue.

9. Will resetting the OBDII system clear code U1408?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the implausible brake signal remains unresolved, the code is likely to reappear.

10. Is it safe to continue driving with OBDII code U1408 until it's fixed?

- It's not recommended to drive with this code present, as it may indicate a problem with the brake system that could compromise safety. It's best to address the issue promptly.