AutoCodes – GMC – U1048 GMC

U1048 GMC 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 GMC 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 657

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

What does this mean?

What are the Possible Causes of the DTC U1048 GMC?

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 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 U1048 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 U1048 GMC Code

1. What are the common symptoms of OBDII code U1048 GMC?

- Common symptoms include loss of communication with the rear wheel steering control module, malfunction indicator light (MIL) illumination, and potential issues with rear wheel steering functionality.

2. What are the possible causes of OBDII code U1048 GMC?

- Possible causes include a faulty rear wheel steering control module, damaged wiring or connectors, communication bus issues, or a software glitch in the vehicle's system.

3. How can I diagnose the issue related to code U1048 GMC?

- A thorough diagnostic scan using an OBDII scanner is recommended to retrieve the specific trouble codes. Additionally, inspecting the wiring, connectors, and module for any visible damage can help identify the problem.

4. Is it safe to drive with OBDII code U1048 GMC active?

- It is generally not recommended to drive with this code active, as it may affect the rear wheel steering system's operation, potentially leading to safety concerns or further damage to the vehicle.

5. How can I reset OBDII code U1048 GMC?

- Resetting the code typically involves using an OBDII scanner to clear the trouble codes after the underlying issue has been diagnosed and repaired. Simply clearing the code without addressing the root cause may result in it reappearing.

6. Can a DIY enthusiast repair OBDII code U1048 GMC?

- While some DIY enthusiasts may be able to diagnose and repair simple issues related to this code, it is recommended to consult a professional mechanic or technician for a comprehensive diagnosis and repair to ensure the problem is properly resolved.

7. What are the repair options for OBDII code U1048 GMC?

- Repair options may include replacing the rear wheel steering control module, repairing or replacing damaged wiring or connectors, addressing communication bus issues, and updating software as needed.

8. How much does it cost to fix OBDII code U1048 GMC?

- The cost of fixing this code can vary depending on the specific cause of the issue, parts needed for repair, labor costs, and whether the repair is done at a dealership or an independent repair shop. It is advisable to obtain quotes from multiple sources.

9. Are there any recalls or technical service bulletins related to OBDII code U1048 GMC?

- It is advisable to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins related to this code, as they may provide important information or potential solutions for the issue.

10. How can I prevent OBDII code U1048 GMC from occurring in the future?

- Regular maintenance, including checking and ensuring proper functioning of the rear wheel steering system, inspecting wiring and connectors for damage, and addressing any warning signs promptly, can help prevent the recurrence of this code.