AutoCodes – GMC – U1889 GMC

U1889 GMC Code - Hybrid Control Module Lost Communication With Body Control Module

Quick Answer

Modules connected to the class 2 and high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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: U1889 GMC indicates Hybrid Control Module Lost Communication With Body Control Module.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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 654

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 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1889 GMC Description

Modules connected to the class 2 and 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 Diagnostic Trouble Code (DTC) is reported on a class 2 link to the scan tool by Powertrain Control Module (PCM) even if they may be set by different modules. The DTC will set when a node alive message has not been received from an identified module within the last 5 seconds after establishing class 2 serial data communication, or a supervised high-speed GMLAN message has not been received.

OBDII Code U1889 GMC - Hybrid Control Module Lost Communication With Body Control Module - AutoCodes.com — U1889 GMC Code - Hybrid Control Module Lost Communication With Body Control Module

What does this mean?

What are the Possible Causes of the DTC U1889 GMC?

Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection
Faulty Hybrid Control Module (HCM)

How to Fix the DTC U1889 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 U1889 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 U1889 GMC Code

1. What are the common symptoms of OBDII code U1889 GMC?

- Common symptoms include issues with starting the vehicle, loss of power steering, malfunctioning lights, and problems with the hybrid system.

2. What can cause the Hybrid Control Module to lose communication with the Body Control Module?

- Possible causes include wiring issues, loose connections, a faulty control module, or software glitches.

3. How can I diagnose the U1889 GMC code?

- Diagnosis involves using a professional OBDII scanner to retrieve the code, checking for other related codes, and inspecting the wiring and connections between the control modules.

4. Is it safe to continue driving with the U1889 GMC code present?

- It is not recommended to drive the vehicle with this code active, as it can lead to further electrical and hybrid system problems.

5. Can I repair the U1889 GMC code myself?

- Repairing this code typically requires advanced automotive knowledge and specialized tools, so it is best to seek assistance from a professional mechanic.

6. How expensive is it to fix the U1889 GMC code?

- The cost of repairs can vary depending on the underlying issue, but it is advisable to budget for diagnostic fees, parts replacement, and labor costs.

7. Are there any known recalls related to the U1889 GMC code?

- It is advisable to check with the manufacturer or a dealership to see if there are any recalls or technical service bulletins related to this code.

8. Can a low battery voltage trigger the U1889 GMC code?

- Yes, a low battery voltage can potentially cause communication issues between control modules and trigger this code.

9. Will resetting the code make it go away permanently?

- Resetting the code may temporarily clear the error, but if the underlying issue is not addressed, the code is likely to reappear.

10. How long does it typically take to repair the U1889 GMC code?

- The repair time can vary depending on the complexity of the issue, availability of parts, and the workload of the repair shop, but it may take a few hours to a day or more to resolve.