AutoCodes – Buick – U1048 Buick

U1048 Buick Code - Lost Communications With Rear Wheel Steering Control Module

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Rear Wheel Steering Control Module (RWSCM), Rear Wheel Steering Control Module harness is open or shorted, Rear Wheel Steering 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: U1048 Buick indicates Lost Communications With Rear Wheel Steering Control Module.
Common causes: Common causes include Faulty Rear Wheel Steering Control Module (RWSCM), Rear Wheel Steering Control Module harness is open or shorted, Rear Wheel Steering 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 566

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 22, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1048 Buick Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for the state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a Diagnostic Trouble Code (DTC) U1048 is set.

OBDII Code U1048 Buick - Lost Communications With Rear Wheel Steering Control Module - AutoCodes.com — U1048 Buick Code - Lost Communications With Rear Wheel Steering Control Module

What does this mean?

What are the Possible Causes of the DTC U1048 Buick?

Faulty Rear Wheel Steering Control Module (RWSCM)
Rear Wheel Steering Control Module harness is open or shorted
Rear Wheel Steering Control Module circuit poor electrical connection

How to Fix the DTC U1048 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 U1048 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 U1048 Buick Code

1. What does OBDII code U1048 mean on a Buick?

U1048 indicates a loss of communication with the Rear Wheel Steering Control Module, meaning the module isn't sending or receiving data properly on the vehicle's communication network.

2. What are the common symptoms of U1048 on a Buick?

Common symptoms include the rear-wheel steering feature not working, a lit check engine light, stability control warnings, and reduced handling performance.

3. What causes the U1048 code to appear?

The code can be triggered by faulty wiring, a damaged Rear Wheel Steering Control Module, a malfunctioning control module elsewhere on the network, or a communication bus issue.

4. Can I drive my Buick with a U1048 code?

While the vehicle may still be drivable, the rear-wheel steering system and possibly other stability features may not function correctly, which could impact handling and safety.

5. How do I diagnose the U1048 code on my Buick?

Start by inspecting the wiring and connectors to the Rear Wheel Steering Control Module for damage or loose connections. Also, use a scan tool to check for related codes and monitor communication on the CAN bus.

6. How do I fix the U1048 code on my Buick?

Repairs may include fixing damaged wiring or connectors, updating or reprogramming the module, or replacing the Rear Wheel Steering Control Module if it's determined to be faulty.

7. What tools are needed to troubleshoot the U1048 code?

A scan tool with CAN bus diagnostics, a multimeter for checking wiring continuity, and possibly an oscilloscope to monitor communication signals may be required.

8. Can a dead battery cause the U1048 code?

Yes, a weak or dead battery can disrupt communication between modules and potentially trigger the U1048 code. Ensure the battery and charging system are in good condition.

9. Does the U1048 code always mean the Rear Wheel Steering Control Module is bad?

No, the issue could be due to wiring problems, network communication issues, or faults in other connected modules instead of the control module itself.

10. How much does it cost to fix the U1048 code on a Buick?

Repair costs can range from $100 for minor wiring fixes to over $1,000 if the Rear Wheel Steering Control Module needs replacement or reprogramming.