AutoCodes – Buick – P0B4B Buick

P0B4B Buick Code - Hybrid/Electric Vehicle Battery 4 Circuit Performance

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: P0B4B Buick indicates Hybrid/Electric Vehicle Battery 4 Circuit Performance.
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 906

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 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0B4B Buick 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 P0B4B Buick - Hybrid/Electric Vehicle Battery 4 Circuit Performance - AutoCodes.com — P0B4B Buick Code - Hybrid/Electric Vehicle Battery 4 Circuit Performance

What does this mean?

What are the Possible Causes of the DTC P0B4B Buick?

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

How to Fix the DTC P0B4B 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 P0B4B 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 P0B4B Buick Code

What does OBDII code P0B4B mean for a Buick?

Code P0B4B indicates a performance issue with the Hybrid/Electric Vehicle Battery 4 Circuit, often signaling a problem with battery module 4 or its associated circuitry.

What are the common symptoms of code P0B4B?

Typical symptoms include reduced fuel economy, diminished battery performance, warning lights on the dashboard, and possible loss of hybrid or electric vehicle functionality.

What causes code P0B4B in a Buick?

Common causes include faulty battery modules, damaged wiring or connectors in the battery circuit, or issues with the hybrid battery control module.

Can I drive my Buick with code P0B4B?

While you may still be able to drive the vehicle, reduced hybrid/electric performance can lead to decreased efficiency and potential safety risks. Prompt diagnosis and repair are recommended.

How is code P0B4B diagnosed?

Technicians typically use a scan tool to read detailed data from the hybrid battery system, inspect wiring and connectors, and test the affected battery module for proper voltage and resistance.

What repairs can fix code P0B4B?

Repairs may include replacing the faulty battery module, repairing damaged wiring or connectors, or reprogramming or replacing the hybrid battery control module.

How much does it cost to repair code P0B4B on a Buick?

Costs vary depending on the specific repair needed. Battery module replacement can range from $1,000 to $5,000, while wiring repairs may be less expensive.

Can a weak 12V battery cause code P0B4B?

While unlikely, a weak 12V battery can sometimes affect hybrid system diagnostics. Ensure the 12V battery is in good condition before further troubleshooting.

Does code P0B4B require specialized equipment for repair?

Yes, diagnosing and repairing hybrid battery circuit issues often requires specialized diagnostic tools and expertise in hybrid systems.

Can P0B4B be prevented?

Routine inspection of the hybrid battery system, maintaining proper cooling, and avoiding extreme temperatures can help minimize the chances of this code appearing.