AutoCodes – GMC – U1549 GMC

U1549 GMC 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 GMC 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 2,074

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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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 GMC 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 GMC - Body Control Module Lost Communication With Rear Wiper Motor On LIN Bus - AutoCodes.com — U1549 GMC 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 GMC?

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 GMC?

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 GMC 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 GMC Code

1. What are the common symptoms of OBDII code U1549 in a GMC vehicle?

- Common symptoms include the rear wiper not functioning, erratic rear wiper operation, warning lights on the dashboard, and issues with other body control functions.

2. What does the OBDII code U1549 GMC mean?

- The code indicates that the Body Control Module has lost communication with the rear wiper motor on the LIN Bus network.

3. What are the possible causes of the Body Control Module losing communication with the rear wiper motor?

- Potential causes include a faulty rear wiper motor, damaged wiring or connectors, a malfunctioning Body Control Module, or issues with the LIN Bus network.

4. How can I diagnose the cause of the communication loss between the Body Control Module and the rear wiper motor?

- Diagnosing the issue may involve conducting a visual inspection of wiring and connectors, testing the rear wiper motor for functionality, and using a scan tool to check for communication errors.

5. Is it safe to continue driving with OBDII code U1549 present in my GMC vehicle?

- It is generally safe to drive with this code, but it is recommended to address the issue promptly to ensure proper functioning of the rear wiper and other related systems.

6. Can I repair OBDII code U1549 GMC on my own, or should I seek professional help?

- Depending on your experience and access to tools, you may be able to address this issue on your own by checking wiring connections and components. However, seeking professional help is recommended for more complex diagnostics and repairs.

7. Are there any quick tips for troubleshooting OBDII code U1549 in a GMC vehicle?

- Quick tips include checking fuses related to the rear wiper system, inspecting wiring for visible damage, and resetting the Body Control Module by disconnecting the battery for a few minutes.

8. Will resetting the Body Control Module clear the U1549 code?

- Resetting the Body Control Module may clear the code temporarily, but if the underlying issue causing the communication loss is not resolved, the code is likely to reappear.

9. How much does it typically cost to repair OBDII code U1549 in a GMC vehicle?

- Repair costs can vary depending on the specific cause of the issue, but they may range from a few hundred dollars for simple fixes like wiring repairs to over a thousand dollars for more complex repairs involving module replacement.

10. Can OBDII code U1549 in a GMC be prevented in the future?

- Regular maintenance checks, ensuring proper wiring connections, and addressing any issues promptly can help prevent the recurrence of the communication loss between the Body Control Module and the rear wiper motor.