AutoCodes – Generic – U01A0

U01A0 Code - Lost Communication with Hybrid/EV Battery Interface Control Module 1

Quick Answer

This diagnostic monitors the internal battery communication status between the Hybrid/EV Powertrain Control Module 2 and the Hybrid/EV Battery Interface Control Modules. Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface 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: U01A0 indicates Lost Communication with Hybrid/EV Battery Interface Control Module 1.
Common causes: Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface 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 417

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 Jul 21, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U01A0 Description

This diagnostic monitors the internal battery communication status between the Hybrid/EV Powertrain Control Module 2 and the Hybrid/EV Battery Interface Control Modules. The diagnostic monitors Hybrid/EV Battery Interface Control Modules data availability whenever this private communications bus is active. The communication network between Hybrid/EV Powertrain Control Module 2 and Hybrid/EV Battery Interface Control Modules is in a daisy-chain architecture. Therefore, a break at any point in the communication bus results in a loss of Hybrid/EV Battery Interface Control Modules communication with the Hybrid/EV Powertrain Control Module 2. If any data is received, the diagnostic will report a pass. If no data is received for greater than 4.5 s, the Hybrid/EV Powertrain Control Module 2 will attempt to initiate the Hybrid/EV Battery Interface Control Modules into a communication mode where the Hybrid/EV Battery Interface Control Modules can perform their own internal communication loop back, bypassing the daisy-chain. If this is the first Hybrid/EV Battery Interface Control Module in the daisy-chain that the Hybrid/EV Powertrain Control Module 2 cannot re-establish communication with, this diagnostic will fail. The Diagnostic Trouble Code (DTC) will be set when the Hybrid/EV Powertrain Control Module 2 has not received data from the Hybrid/EV Battery Interface Control Module 1 for more than 4.5 s.

OBDII Code U01A0 - Lost Communication with Hybrid/EV Battery Interface Control Module 1 - AutoCodes.com — U01A0 Code - Lost Communication with Hybrid/EV Battery Interface Control Module 1

What does this mean?

What are the Possible Causes of the DTC U01A0?

Faulty Hybrid/EV Battery Interface Control Module
Hybrid/EV Battery Interface Control Module harness is open or shorted
Hybrid/EV Battery Interface Control Module circuit poor electrical connection

How to Fix the DTC U01A0?

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 U01A0 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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Information for Specific Makes

U01A0 Buick — Lost Communication with Hybrid/EV Battery Interface Control Module 1
U01A0 Cadillac — Lost Communication with Hybrid/EV Battery Interface Control Module 1
U01A0 Chevrolet — Lost Communication with Hybrid/EV Battery Interface Control Module 1
U01A0 GMC — Lost Communication with Hybrid/EV Battery Interface Control Module 1

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 U01A0 Code

What does OBDII code U01A0 mean?

Code U01A0 indicates a loss of communication between the vehicle's main computer and the Hybrid/EV Battery Interface Control Module 1.

What are the common symptoms of U01A0?

Symptoms include warning lights on the dashboard, reduced hybrid or EV performance, and possible failure to charge the battery.

What causes code U01A0 to appear?

Common causes include faulty wiring or connectors, a failed Hybrid/EV Battery Interface Control Module, or issues with the vehicle's communication network.

Can a dead battery cause code U01A0?

Yes, a weak or dead hybrid/EV battery can trigger communication issues and result in the U01A0 code.

How can I diagnose U01A0?

Start by inspecting the wiring and connectors for damage or corrosion, then use a diagnostic tool to check for communication errors with the Hybrid/EV Battery Interface Control Module.

Is it safe to drive with code U01A0?

Driving with this code may lead to reduced performance or further damage to hybrid/EV components, so itâ€™s best to address it promptly.

How do I fix code U01A0?

Repairs may involve fixing damaged wiring, replacing the Hybrid/EV Battery Interface Control Module, or reprogramming the module if needed.

Can a software update resolve code U01A0?

In some cases, a software update or reprogramming of the control module can restore communication and resolve the issue.

How much does it cost to repair code U01A0?

Repair costs vary depending on the issue, ranging from $100 for wiring repairs to over $1,000 for module replacement.

Do I need a professional mechanic to fix code U01A0?

While basic checks can be done at home, diagnosing and repairing communication faults often require specialized tools and expertise, so consulting a mechanic is recommended.