AutoCodes – Buick – U1549 Buick

U1549 Buick Code - Body Control Module Lost Communication With Rear Wiper Motor On LIN Bus

Quick Answer

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. Common causes include Faulty Rear Wiper Motor, Rear Wiper Motor harness is open or shorted, Rear Wiper Motor 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: U1549 Buick indicates Body Control Module Lost Communication With Rear Wiper Motor On LIN Bus.
Common causes: Common causes include Faulty Rear Wiper Motor, Rear Wiper Motor harness is open or shorted, Rear Wiper Motor 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 505

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 Jun 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1549 Buick Description

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. The serial data is transmitted over a LIN circuit between a master control module and other LIN devices within a particular subsystem. If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) will set when a supervised periodic message to the Body Control Module (BCM) from the Rear Wiper Motor has not been received.

OBDII Code U1549 Buick - Body Control Module Lost Communication With Rear Wiper Motor On LIN Bus - AutoCodes.com — U1549 Buick Code - Body Control Module Lost Communication With Rear Wiper Motor On LIN Bus

What does this mean?

What are the Possible Causes of the DTC U1549 Buick?

Faulty Rear Wiper Motor
Rear Wiper Motor harness is open or shorted
Rear Wiper Motor circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC U1549 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 U1549 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 U1549 Buick Code

1. What does the OBDII code U1549 mean on a Buick?

U1549 indicates that the Body Control Module (BCM) lost communication with the rear wiper motor on the Local Interconnect Network (LIN) bus.

2. What are the common symptoms of the U1549 code in a Buick?

Symptoms may include the rear wiper not functioning, warning lights on the dashboard, or intermittent electrical issues.

3. What causes the U1549 code to appear?

Common causes include a faulty rear wiper motor, damaged LIN bus wiring, corroded connectors, or a malfunctioning Body Control Module.

4. Can I still drive my Buick with a U1549 code?

Yes, the vehicle is usually drivable, but the rear wiper may not function properly, which can affect visibility in adverse weather.

5. How do I diagnose the U1549 code on my Buick?

Start by inspecting the rear wiper motor, checking the LIN bus wiring for damage, and testing the connectors for corrosion or loose connections.

6. How do I fix the U1549 code on my Buick?

Repairs may include replacing a faulty rear wiper motor, repairing damaged LIN bus wiring, cleaning or replacing corroded connectors, or reprogramming the BCM.

7. Is the U1549 code specific to Buick vehicles?

No, U1549 is a generic communication code, but its specific meaning can vary by manufacturer. On a Buick, it relates to the rear wiper motor and BCM.

8. Can a blown fuse cause the U1549 code?

Yes, a blown fuse in the rear wiper circuit can disrupt communication and trigger the U1549 code.

9. Will clearing the U1549 code fix the issue?

Clearing the code may temporarily reset the warning, but the underlying issue must be resolved to prevent the code from returning.

10. Do I need to replace the BCM if I get a U1549 code?

Not necessarily. The issue is often with the rear wiper motor or wiring. The BCM should be tested only if other solutions donâ€™t resolve the problem.