AutoCodes – GMC – P1B29 GMC

P1B29 GMC Code - Hybrid/Electric Vehicle Battery 28 Circuit

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: P1B29 GMC indicates Hybrid/Electric Vehicle Battery 28 Circuit.
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.

Save to My Repairs My Repairs

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

Code Popularity 901

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
Add Comment

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

Code P1B29 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 P1B29 GMC - Hybrid/Electric Vehicle Battery 28 Circuit - AutoCodes.com — P1B29 GMC Code - Hybrid/Electric Vehicle Battery 28 Circuit

What does this mean?

What are the Possible Causes of the DTC P1B29 GMC?

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

How to Fix the DTC P1B29 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 P1B29 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.

Need more information about the P1B29 GMC code?

Need more information on how to fix the P1B29 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1B29 GMC 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 P1B29 GMC Code

What does the OBDII code P1B29 mean for GMC vehicles?

P1B29 indicates a problem with the Hybrid/Electric Vehicle Battery 28 Circuit, which may affect the performance of the vehicle's hybrid or electric powertrain.

What are common symptoms of the P1B29 code?

Common symptoms include a warning light on the dashboard, reduced power or acceleration, and possible issues with the electric vehicle's battery performance.

What could cause the P1B29 code to trigger?

Causes may include a faulty battery management system, damaged wiring or connectors in the battery circuit, or a malfunctioning hybrid battery.

How can I diagnose the P1B29 code?

Using an OBDII scanner, you can read the code and check for any additional codes. Inspect wiring, connectors, and the battery management system for any visible issues.

Is it safe to drive my GMC vehicle with the P1B29 code?

While it might be safe for short distances, it's advisable to have the issue diagnosed and repaired as it may affect the vehicle's hybrid or electric performance.

What repairs are commonly needed for the P1B29 code?

Repairs may include replacing damaged wiring, fixing or replacing the battery management system, or addressing issues with the hybrid battery itself.

Can I clear the P1B29 code without fixing the problem?

Clearing the code may turn off the warning light temporarily, but the underlying issue will likely cause the code to return, and driving the vehicle may lead to further issues.

How much does it typically cost to repair the P1B29 code?

Repair costs can vary widely based on the specific issue but may range from a few hundred to several thousand dollars, depending on whether wiring, management systems, or batteries need replacement.

Should I take my GMC to a dealership or a local mechanic for P1B29 repairs?

Both options are valid, but a dealership may have more specific expertise with hybrid systems, while a qualified local mechanic can also provide reliable repairs at potentially lower costs.