AutoCodes – GMC – P1BA9 GMC

P1BA9 GMC Code - Hybrid/Electric Vehicle Battery 66 Circuit Low Voltage

Quick Answer

The Hybrid/Electric Vehicle battery pack contains 288 cells. Common causes include Faulty Hybrid/Electric Vehicle Battery Pack, Faulty Hybrid/Electric Vehicle Battery Interface Control Module. 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: P1BA9 GMC indicates Hybrid/Electric Vehicle Battery 66 Circuit Low Voltage.
Common causes: Common causes include Faulty Hybrid/Electric Vehicle Battery Pack, Faulty Hybrid/Electric Vehicle Battery Interface Control Module.
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 903

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 Mar 12, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1BA9 GMC Description

The Hybrid/Electric Vehicle battery pack contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the hybrid/EV battery pack assembly. These cell groups are electrically connected in-series. Each individual cell group is rated at 3.7 V, for a nominal system voltage of 355 V direct current. The battery cells are also grouped together into three sections. The first 90 cells/30 cell groups make up battery section one. This section is adjacent to the cowl and contains batteries 67 through to 96. Battery section two is located behind section one. It is made up of 72 cells/24 cell groups and contains batteries 43 through to 66. The transverse battery section is section number three, it is made up of the remaining 126 cells/42 cell groups and contains batteries 1 through to 42. The three battery sections are individually serviceable components.
The battery energy control module monitors the voltage of the 96 battery cell groups through the four hybrid/EV battery interface control modules. Voltage sense circuits are attached to each individual cell group, and these sense circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness joins this connector to a hybrid/EV battery interface control module, also located on the top surface of the battery section. The hybrid/EV battery interface control module encodes the voltage reading and transmits it to the battery energy control module through the battery control harness. There is one hybrid/EV battery interface control module located on battery sections one and two, and two hybrid/EV battery interface control modules associated with battery section three. The hybrid/EV battery interface control module, battery energy control module wiring harness, auxiliary battery wiring harness, and battery energy control module are all considered serviceable components.
The battery energy control module will determine when a fault condition is present. Diagnostics and system status are communicated from the battery energy control module to hybrid/EV powertrain control module 2 through serial data. The hybrid/EV powertrain control module 2 is the host controller for diagnostic trouble code information.

OBDII Code P1BA9 GMC - Hybrid/Electric Vehicle Battery 66 Circuit Low Voltage - AutoCodes.com — P1BA9 GMC Code - Hybrid/Electric Vehicle Battery 66 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1BA9 GMC?

Faulty Hybrid/Electric Vehicle Battery Pack
Faulty Hybrid/Electric Vehicle Battery Interface Control Module

How to Fix the DTC P1BA9 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 P1BA9 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 P1BA9 GMC Code

1. What does the OBDII code P1BA9 mean on a GMC vehicle?

P1BA9 indicates a "Hybrid/Electric Vehicle Battery 66 Circuit Low Voltage," meaning the control module has detected a low-voltage issue in a specific battery circuit.

2. What are the symptoms of code P1BA9 in a GMC hybrid or electric vehicle?

Common symptoms include reduced vehicle performance, warning lights on the dashboard, limited electric driving range, and possible failure to start.

3. What causes the P1BA9 code on a GMC hybrid or electric vehicle?

The code can be caused by faulty battery cells, damaged wiring or connectors in the battery circuit, a failing battery control module, or corrosion in the electrical connections.

4. Can a weak auxiliary 12V battery trigger the P1BA9 code?

No, the P1BA9 code specifically refers to the hybrid or high-voltage battery system and its circuits, not the auxiliary 12V battery.

5. Is it safe to drive a GMC vehicle with the P1BA9 code?

It is not recommended to drive the vehicle as it may experience reduced performance or further damage to the hybrid system. Seek diagnosis and repair promptly.

6. How do technicians diagnose the P1BA9 code on a GMC vehicle?

Technicians use a scan tool to read the code, inspect the battery circuit wiring and connectors, test individual battery cells, and verify the operation of the battery control module.

7. How is the P1BA9 code repaired on a GMC hybrid or electric vehicle?

Repairs may involve replacing damaged wiring, cleaning corroded connections, replacing faulty battery cells, or reprogramming or replacing the battery control module.

8. Can the P1BA9 code be cleared without repairs?

Clearing the code without addressing the root cause may result in the code returning and could potentially worsen the issue over time.

9. What tools are needed to fix the P1BA9 code in a GMC hybrid vehicle?

Tools typically include a diagnostic scan tool, a multimeter for testing voltage, and possibly specialized equipment for handling high-voltage battery systems.

10. Does the P1BA9 code mean the hybrid battery needs to be replaced?

Not necessarily; it could be a wiring or control module issue. A proper diagnosis is required to determine if the battery needs replacement or if a smaller repair will resolve the problem.