AutoCodes – Generic – U0209

U0209 Code - Lost Communication With Seat Control Module '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 Seat Control Module 'B', Seat Control Module 'B' harness is open or shorted, Seat Control Module '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: U0209 indicates Lost Communication With Seat Control Module 'B'.
Common causes: Common causes include Faulty Seat Control Module 'B', Seat Control Module 'B' harness is open or shorted, Seat Control Module '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 6,107

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 03, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0209 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 Seat Control Module 'B' has not been received.

OBDII Code U0209 - Lost Communication With Seat Control Module 'B' - AutoCodes.com — U0209 Code - Lost Communication With Seat Control Module 'B'

What does this mean?

What are the Possible Causes of the DTC U0209?

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

How to Fix the DTC U0209?

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 U0209 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 U0209 code?

Need more information on how to fix the U0209 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0209 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U0209 Buick — Lost Communication With Front Seat Heating Control Module
U0209 Cadillac — Lost Communication With Front Seat Heating Control Module
U0209 Chevrolet — Lost Communication With Front Seat Heating Control Module
U0209 Chrysler — Lost Communication With Memory Seat Control Module
U0209 Dodge — Lost Communication With Memory Seat Control Module
U0209 GMC — Lost Communication With Front Seat Heating Control Module
U0209 Jeep — Lost Communication With Memory Seat Control Module
U0209 RAM — Lost Communication With Memory Seat 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 U0209 Code

1. What are common symptoms of OBDII code U0209 (Lost Communication With Seat Control Module 'B')?

- Common symptoms include non-functioning seat controls, inability to adjust seat position, and warning lights on the dashboard.

2. What are possible causes of OBDII code U0209?

- Possible causes include a faulty seat control module, damaged wiring or connectors, software issues, or a malfunctioning CAN bus communication system.

3. How can I diagnose the issue related to OBDII code U0209?

- Diagnose the issue by checking the seat control module for power and ground, inspecting wiring for damage, and using a diagnostic scanner to communicate with the module.

4. Can OBDII code U0209 be fixed without professional help?

- Depending on the cause, some simple fixes like checking and repairing damaged wiring or connectors may be possible without professional help. However, complex issues may require a professional diagnosis.

5. What steps can I take to repair OBDII code U0209?

- Repair steps may include replacing the seat control module, repairing damaged wiring, updating software, or resetting the system using a diagnostic tool.

6. Is it safe to continue driving with OBDII code U0209 present?

- It is not recommended to continue driving with this code present, as it may indicate a malfunction in the vehicle's seat control system that could potentially lead to safety issues.

7. How can I prevent OBDII code U0209 from occurring in the future?

- To prevent this code from occurring, regularly check and maintain the seat control system components, ensure proper wiring connections, and address any warning signs promptly.

8. Can OBDII code U0209 affect other vehicle systems?

- Yes, this code may indicate a communication issue within the vehicle's network, which could potentially affect other systems relying on the same CAN bus communication.

9. Will resetting the OBDII code U0209 clear the issue permanently?

- Resetting the code may clear the warning temporarily, but if the underlying issue causing the communication loss is not fixed, the code is likely to reappear.

10. How much does it typically cost to repair OBDII code U0209?

- The cost of repairing this code can vary depending on the specific cause and the labor rates of the repair shop. It is recommended to get a diagnosis and estimate from a professional technician.