AutoCodes – Generic – U11D2

U11D2 Code - Lost Brake Signal

Quick Answer

This diagnostic checks the validity of the brake switch message which is sent by the Anti-lock Braking System (ABS) Module via Controller Area Network (CAN) network. Common causes include Faulty Powertrain Control Module (PCM), Faulty Anti-lock Braking System (ABS) Module, Faulty Transmission Control Module (TCM). 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: U11D2 indicates Lost Brake Signal.
Common causes: Common causes include Faulty Powertrain Control Module (PCM), Faulty Anti-lock Braking System (ABS) Module, Faulty Transmission Control Module (TCM).
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 918

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 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U11D2 Description

This diagnostic checks the validity of the brake switch message which is sent by the Anti-lock Braking System (ABS) Module via Controller Area Network (CAN) network. The diagnostic checks the validity by performing a CRC and message counter check to verify the brake switch message is continuously updated by the ABS module and it has a valid value. A signal toggle bit and a signal parity bit are sent by the ABS module within the CAN message. In order to be sure the message content is continuously updated, the value of the toggle bit changes from 0 to 1 and vice versa every two messages. In order to be sure the message content is valid, the parity bit value is set so that the sum of specific signal bits (PcmBrkSw) of the message content plus the toggle bit plus the parity bit is an even number. If the toggle bit value does not change or the signal parity is not verified for a calibrated amount of time then the Diagnostic Trouble Code (DTC) U11D2 is set.

OBDII Code U11D2 - Lost Brake Signal - AutoCodes.com — U11D2 Code - Lost Brake Signal

What does this mean?

What are the Possible Causes of the DTC U11D2?

Faulty Powertrain Control Module (PCM)
Faulty Anti-lock Braking System (ABS) Module
Faulty Transmission Control Module (TCM)

How to Fix the DTC U11D2?

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 U11D2 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 U11D2 code?

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Information for Specific Makes

U11D2 Chrysler — Lost Brake Signal
U11D2 Dodge — Lost Brake Signal
U11D2 Fiat — Lost Brake Signal
U11D2 Jeep — Lost Brake Signal
U11D2 RAM — Lost Brake Signal

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 U11D2 Code

1. What are the common symptoms of OBDII code U11D2 (Lost Brake Signal)?

- Common symptoms include the illumination of the brake warning light on the dashboard, loss of brake lights functionality, and potential issues with the anti-lock braking system (ABS).

2. What are the possible causes of OBDII code U11D2 (Lost Brake Signal)?

- Possible causes may include a faulty brake light switch, damaged wiring or connectors in the brake light circuit, a malfunctioning ABS module, or a problem with the brake pedal position sensor.

3. How can I diagnose the root cause of OBDII code U11D2 (Lost Brake Signal)?

- You can diagnose the issue by checking the brake light switch for proper operation, inspecting the wiring and connectors for any damage, testing the brake pedal position sensor, and scanning the ABS module for any related error codes.

4. Can I still drive my vehicle with OBDII code U11D2 (Lost Brake Signal) active?

- It is not recommended to drive the vehicle with this code active, as it indicates a potential loss of brake signal which can compromise safety. Have the issue diagnosed and repaired as soon as possible.

5. How do I repair OBDII code U11D2 (Lost Brake Signal)?

- The repair process involves identifying and addressing the root cause, which may include replacing the brake light switch, repairing damaged wiring or connectors, recalibrating the brake pedal position sensor, or replacing a faulty ABS module.

6. Will resetting the OBDII code U11D2 (Lost Brake Signal) make the issue go away?

- Resetting the code may temporarily clear the warning light, but it will not fix the underlying problem causing the lost brake signal. It's important to diagnose and repair the issue to ensure safe operation of the braking system.

7. Can a DIY enthusiast address OBDII code U11D2 (Lost Brake Signal) at home?

- Depending on the cause of the issue, some DIY enthusiasts with the necessary tools and knowledge may be able to address this code at home. However, complex issues may require professional diagnosis and repair.

8. Is OBDII code U11D2 (Lost Brake Signal) a serious problem?

- Yes, OBDII code U11D2 indicating a lost brake signal is a serious problem that can affect the functionality of the brake system, including brake lights and ABS. Prompt attention and repair are essential for safety.

9. How much does it typically cost to repair OBDII code U11D2 (Lost Brake Signal)?

- The cost of repair can vary depending on the root cause of the issue, labor rates, and replacement parts needed. It's advisable to obtain quotes from mechanics or repair shops for an accurate estimate.

10. Can OBDII code U11D2 (Lost Brake Signal) lead to other issues if not addressed promptly?

- If left unaddressed, OBDII code U11D2 can potentially lead to safety hazards due to compromised brake signal transmission. It is crucial to address the issue promptly to prevent further complications.