AutoCodes – Generic – U11C9

U11C9 Code - Lost Left Front Wheel Speed Message

Quick Answer

This diagnostic checks the availability of the left front wheel speed signal which is sent by the Electronic Stability Program (ESP) via a Controller Area Network (CAN) message. Common causes include Faulty Powertrain Control Module (PCM), Faulty Anti-Lock Brake System (ABS) 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: U11C9 indicates Lost Left Front Wheel Speed Message.
Common causes: Common causes include Faulty Powertrain Control Module (PCM), Faulty Anti-Lock Brake System (ABS) 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 1,041

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 U11C9 Description

This diagnostic checks the availability of the left front wheel speed signal which is sent by the Electronic Stability Program (ESP) via a Controller Area Network (CAN) message. The diagnostic checks the availability by checking the valid bit. The Diagnostic Trouble Code (DTC) sets when the read value does not match the written value in any RAM location.

OBDII Code U11C9 - Lost Left Front Wheel Speed Message - AutoCodes.com — U11C9 Code - Lost Left Front Wheel Speed Message

What does this mean?

What are the Possible Causes of the DTC U11C9?

Faulty Powertrain Control Module (PCM)
Faulty Anti-Lock Brake System (ABS) Module

How to Fix the DTC U11C9?

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 U11C9 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 U11C9 code?

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Need Help with the Code?

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Information for Specific Makes

U11C9 Chrysler — Lost Left Front Wheel Speed Message
U11C9 Dodge — Lost Left Front Wheel Speed Message
U11C9 Jeep — Lost Left Front Wheel Speed Message
U11C9 RAM — Lost Left Front Wheel Speed Message

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 U11C9 Code

What does the OBDII code U11C9 mean?

The OBDII code U11C9 indicates a "Lost Left Front Wheel Speed Message," which means the vehicle's control module is not receiving data from the left front wheel speed sensor.

What are common symptoms of the U11C9 code?

Common symptoms include the ABS warning light illuminating, traction control issues, erratic speedometer readings, and possibly impaired braking performance.

What could cause the U11C9 code to trigger?

Causes may include a faulty left front wheel speed sensor, damaged wiring or connectors, corrosion, or issues within the ABS control module.

How can I diagnose the U11C9 code?

To diagnose the U11C9 code, check for any visible damage to the left front wheel speed sensor and its wiring, use a multimeter to test the sensor for proper resistance, and scan for other related trouble codes.

What repairs are typically needed for the U11C9 code?

Repairs can include replacing the left front wheel speed sensor, repairing damaged wiring or connectors, or addressing any faults in the ABS control module.

Is it safe to drive with a U11C9 code?

While it may be possible to drive with the U11C9 code, it is not recommended due to potential issues with ABS and traction control systems, which could affect vehicle safety.

How can I prevent the U11C9 code from recurring?

To prevent recurrence, ensure regular maintenance of the vehicle's braking and wheel speed sensor systems, promptly address any warning lights, and keep connections clean and free from corrosion.

Can I clear the U11C9 code without fixing the issue?

Yes, you can clear the code using an OBDII scanner, but if the underlying issue is not resolved, the code will likely return.

Will the U11C9 code affect my vehicle's performance?

Yes, the U11C9 code can affect vehicle performance by disabling ABS and traction control, which may lead to decreased handling and braking efficiency, especially in slippery conditions.