AutoCodes – Generic – U0249

U0249 Code - Lost Communication With Entertainment Control Module Rear 'B'

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Faulty Entertainment Control Module Rear 'B', Entertainment Control Module Rear 'B' harness is open or shorted, Entertainment Control Module Rear 'B' 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: U0249 indicates Lost Communication With Entertainment Control Module Rear 'B'.
Common causes: Common causes include Faulty Entertainment Control Module Rear 'B', Entertainment Control Module Rear 'B' harness is open or shorted, Entertainment Control Module Rear 'B' 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 9,031

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 Apr 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0249 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Entertainment Control Module Rear 'B' has not been received.

OBDII Code U0249 - Lost Communication With Entertainment Control Module Rear 'B' - AutoCodes.com — U0249 Code - Lost Communication With Entertainment Control Module Rear 'B'

What does this mean?

What are the Possible Causes of the DTC U0249?

Faulty Entertainment Control Module Rear 'B'
Entertainment Control Module Rear 'B' harness is open or shorted
Entertainment Control Module Rear 'B' circuit poor electrical connection

How to Fix the DTC U0249?

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 U0249 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 U0249 code?

Need more information on how to fix the U0249 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0249 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U0249 Buick — Lost Communication With Rear Entertainment Control Module
U0249 Cadillac — Lost Communication With Rear Entertainment Control Module
U0249 Chevrolet — Lost Communication With Rear Entertainment Control Module
U0249 Chrysler — Lost Communication With Last Row Vehicle Entertainment Control Module
U0249 Dodge — Lost Communication With Last Row Vehicle Entertainment Control Module
U0249 GMC — Lost Communication With Rear Entertainment Control Module
U0249 Jeep — Lost Communication With Last Row Vehicle Entertainment Control Module
U0249 RAM — Lost Communication With Last Row Vehicle Entertainment Control Module

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 U0249 Code

1. What does OBDII code U0249 mean?

U0249 indicates a loss of communication between the vehicle's main control module and the rear entertainment control module 'B'.

2. What are the common symptoms of code U0249?

Symptoms may include a non-functional rear entertainment system, unresponsive controls, or intermittent issues with audio or video playback.

3. What causes code U0249 to appear?

This code can be triggered by faulty wiring or connectors, a failed rear entertainment control module, or communication network issues within the vehicle.

4. Can a dead battery cause U0249?

Yes, a dead or weak battery can disrupt module communication and potentially cause this code.

5. How can I diagnose code U0249?

Start by inspecting the wiring and connectors related to the rear entertainment control module. Use a diagnostic scanner to check for other related communication codes.

6. Can I clear code U0249 without fixing the issue?

Clearing the code without addressing the root cause may temporarily remove it, but it will likely return if the underlying problem persists.

7. Is it safe to drive with code U0249?

Yes, this code typically does not affect the vehicleâ€™s drivability, but you may lose functionality in the rear entertainment system.

8. How do I fix code U0249?

Repairs may involve reconnecting or replacing damaged wiring, updating or reprogramming the control module, or replacing a faulty rear entertainment control module.

9. Will updating the vehicleâ€™s software fix code U0249?

Sometimes, a software update or reprogramming of the control modules can resolve communication issues related to this code.

10. How much does it cost to repair code U0249?

The repair cost varies depending on whether the issue is wiring-related, requires module replacement, or involves reprogramming. It can range from $100 to $1,000 or more.