AutoCodes – Chevrolet – U189A Chevrolet

U189A Chevrolet Code - DC To DC Converter Control Module 'A' Lost Communication With Hybrid Powertrain 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 Hybrid Powertrain Control Module, Hybrid Powertrain Control Module harness is open or shorted, Hybrid Powertrain 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: U189A Chevrolet indicates DC To DC Converter Control Module 'A' Lost Communication With Hybrid Powertrain Control Module.
Common causes: Common causes include Faulty Hybrid Powertrain Control Module, Hybrid Powertrain Control Module harness is open or shorted, Hybrid Powertrain 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 772

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 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code U189A Chevrolet 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 U189A Chevrolet - DC To DC Converter Control Module 'A' Lost Communication With Hybrid Powertrain Control Module - AutoCodes.com — U189A Chevrolet Code - DC To DC Converter Control Module 'A' Lost Communication With Hybrid Powertrain Control Module

What does this mean?

What are the Possible Causes of the DTC U189A Chevrolet?

Faulty Hybrid Powertrain Control Module
Hybrid Powertrain Control Module harness is open or shorted
Hybrid Powertrain Control Module circuit poor electrical connection
Faulty DC To DC Converter Control Module 'A'

How to Fix the DTC U189A Chevrolet?

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 U189A Chevrolet 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.

Need more information about the U189A Chevrolet code?

Need more information on how to fix the U189A Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U189A Chevrolet code diagnosed by a professional: Find a repair shop in your area

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 U189A Chevrolet Code

1. What does the OBDII code U189A for Chevrolet mean?

- The U189A code indicates that the DC to DC converter control module 'A' has lost communication with the hybrid powertrain control module in a Chevrolet vehicle.

2. What are the common symptoms of U189A code in a Chevrolet vehicle?

- Common symptoms include loss of power, illumination of the check engine light, issues with acceleration, and potential difficulty starting the vehicle.

3. What are the possible causes of the U189A code in a Chevrolet?

- The U189A code can be triggered by issues such as a faulty DC to DC converter control module, wiring problems, a malfunctioning hybrid powertrain control module, or a communication network error.

4. How can I diagnose the U189A code in my Chevrolet?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, checking for other related trouble codes, inspecting the wiring for any visible damage, and testing the control modules for proper functionality.

5. Can I continue to drive my Chevrolet with the U189A code present?

- It is not recommended to continue driving the vehicle with the U189A code active, as it may lead to further damage or safety hazards. It's best to address the issue promptly.

6. How can I repair the U189A code in my Chevrolet?

- Repair options may include repairing or replacing any damaged wiring, replacing the faulty DC to DC converter control module or hybrid powertrain control module, and ensuring proper communication between modules.

7. Can a DIY enthusiast fix the U189A code issue in a Chevrolet?

- While some simpler checks like inspecting the wiring connections can be done by a DIY enthusiast, diagnosing and repairing the underlying causes of the U189A code may require advanced knowledge and specialized tools, so professional assistance is recommended.

8. Are there any specific maintenance tips to prevent the U189A code in a Chevrolet?

- Regularly checking the electrical connections, ensuring proper maintenance of the vehicle's systems, and addressing any related trouble codes promptly can help prevent issues leading to the U189A code.

9. Is the U189A code specific to certain Chevrolet models or years?

- The U189A code can occur in various Chevrolet models, especially those equipped with hybrid powertrains and DC to DC converters. Checking the specific vehicle's service manual or consulting a mechanic for model-specific information is recommended.

10. What should I do if the U189A code persists after repair attempts?

- If the U189A code continues to reappear after repair attempts, it's advisable to seek professional help from a certified mechanic or dealership to conduct further diagnostics and resolve the issue effectively.