AutoCodes – Buick – U1023 Buick

U1023 Buick Code - Lost Communications With Hybrid 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 Hybrid Control Module (HCM), Hybrid Control Module harness is open or shorted, Hybrid 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: U1023 Buick indicates Lost Communications With Hybrid Control Module.
Common causes: Common causes include Faulty Hybrid Control Module (HCM), Hybrid Control Module harness is open or shorted, Hybrid 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 397

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 U1023 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) U1023 is set.

OBDII Code U1023 Buick - Lost Communications With Hybrid Control Module - AutoCodes.com — U1023 Buick Code - Lost Communications With Hybrid Control Module

What does this mean?

What are the Possible Causes of the DTC U1023 Buick?

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

How to Fix the DTC U1023 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 U1023 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 U1023 Buick Code

1. What are the common symptoms of OBDII code U1023 in a Buick indicating lost communications with the hybrid control module?

- Common symptoms may include the hybrid system not functioning properly, dashboard warning lights illuminated, and potential loss of power or acceleration.

2. What are some possible causes of OBDII code U1023 in a Buick related to lost communications with the hybrid control module?

- Potential causes may include a faulty hybrid control module, damaged wiring or connectors, low battery voltage, or communication network issues.

3. How can I diagnose the OBDII code U1023 in my Buick signaling lost communications with the hybrid control module?

- Diagnosis typically involves using a professional OBDII scanner to retrieve the code, checking for other related codes, inspecting the wiring and connectors, and testing the hybrid control module.

4. Are there any DIY repair tips for addressing OBDII code U1023 in a Buick due to lost communications with the hybrid control module?

- DIY repair options may include checking and repairing any damaged wiring or connectors, ensuring proper battery voltage, and resetting the system by disconnecting the battery for a few minutes.

5. Is it safe to continue driving my Buick with OBDII code U1023 indicating lost communications with the hybrid control module?

- It is not recommended to continue driving the vehicle as the hybrid system may not function correctly, potentially leading to safety hazards or further damage.

6. How much does it typically cost to repair OBDII code U1023 in a Buick caused by lost communications with the hybrid control module?

- Repair costs can vary depending on the exact cause of the issue, but they may range from a few hundred to over a thousand dollars, including parts and labor.

7. Can a regular mechanic repair OBDII code U1023 in a Buick related to lost communications with the hybrid control module, or is it better to visit a dealership?

- While a regular mechanic may be able to diagnose and repair the issue, visiting a dealership or a hybrid specialist with experience in these systems may provide more accurate and efficient repairs.

8. Are there any preventive measures I can take to avoid encountering OBDII code U1023 in my Buick due to lost communications with the hybrid control module?

- Regular maintenance, such as checking the battery health, inspecting wiring for damage, and keeping the hybrid system components clean, can help prevent issues that may trigger this code.

9. Will resetting the OBDII system clear the U1023 code in a Buick related to lost communications with the hybrid control module?

- Resetting the system may temporarily clear the code, but if the underlying issue causing the lost communication persists, the code is likely to return. It's essential to address the root cause of the problem.

10. Is the OBDII code U1023 in a Buick related to lost communications with the hybrid control module a common issue, or is it more unique to certain models or years?

- The U1023 code can occur in various Buick models with hybrid systems, and while it may not be extremely common, it is essential to address it promptly to ensure the proper functioning of the vehicle.