AutoCodes – Buick – U0204 Buick

U0204 Buick Code - Lost Communication With Right Rear Door Switch Panel Control Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Right Rear Door Switch Panel Control Module, Right Rear Door Switch Panel Control Module harness is open or shorted, Right Rear Door Switch Panel Control 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: U0204 Buick indicates Lost Communication With Right Rear Door Switch Panel Control Module.
Common causes: Common causes include Faulty Right Rear Door Switch Panel Control Module, Right Rear Door Switch Panel Control Module harness is open or shorted, Right Rear Door Switch Panel Control 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 423

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 U0204 Buick Description

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Right Rear Door Switch Panel Control Module has not been received.

OBDII Code U0204 Buick - Lost Communication With Right Rear Door Switch Panel Control Module - AutoCodes.com — U0204 Buick Code - Lost Communication With Right Rear Door Switch Panel Control Module

What does this mean?

What are the Possible Causes of the DTC U0204 Buick?

Faulty Right Rear Door Switch Panel Control Module
Right Rear Door Switch Panel Control Module harness is open or shorted
Right Rear Door Switch Panel Control Module circuit poor electrical connection

How to Fix the DTC U0204 Buick?

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 U0204 Buick 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.

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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 U0204 Buick Code

What does the OBDII code U0204 mean for a Buick?

The code U0204 indicates a loss of communication with the right rear door switch panel control module, which affects the functionality of that door's electronic components.

What are common symptoms of the U0204 code?

Common symptoms include non-functioning power windows, door locks, and interior lights on the right rear door, as well as potential warning lights on the dashboard.

What could cause the U0204 code to trigger?

Causes may include a faulty right rear door switch panel control module, damaged wiring or connectors, or issues with the vehicle's central communication network.

How can I diagnose the U0204 code?

Start by using an OBDII scanner to confirm the code. Then, inspect the wiring and connectors for damage, check the right rear door switch panel for faults, and test the module's functionality.

Is it possible to reset the U0204 code without fixing the issue?

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

What are some common repair solutions for the U0204 code?

Repairs may include replacing the right rear door switch panel control module, repairing damaged wiring or connectors, or reprogramming the module if necessary.

Can I drive my Buick with the U0204 code present?

While it may be safe to drive, you will likely experience issues with the right rear door's electronic functions, and it is advisable to address the problem to avoid further complications.

How much might repairs cost for the U0204 code?

Repair costs can vary widely; replacing the switch panel control module may range from $100 to $400, depending on the vehicle's make and model and labor costs.

Is the U0204 code a common issue in Buicks?

While it is not the most common code, communication issues related to door modules can occur in various Buick models, especially as they age.