AutoCodes – Buick – P1BF4 Buick

P1BF4 Buick Code - Hybrid/Electric Vehicle Battery 91 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: P1BF4 Buick indicates Hybrid/Electric Vehicle Battery 91 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 720

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 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1BF4 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 P1BF4 Buick - Hybrid/Electric Vehicle Battery 91 Circuit Low Voltage - AutoCodes.com — P1BF4 Buick Code - Hybrid/Electric Vehicle Battery 91 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1BF4 Buick?

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

How to Fix the DTC P1BF4 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 P1BF4 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 P1BF4 Buick Code

What does the OBDII code P1BF4 mean on a Buick?

Code P1BF4 indicates "Hybrid/Electric Vehicle Battery 91 Circuit Low Voltage," meaning a low voltage issue has been detected in the hybrid battery circuit.

What are the symptoms of code P1BF4?

Common symptoms include reduced fuel efficiency, limited electric drive capability, warning lights on the dashboard, or decreased overall vehicle performance.

What causes the P1BF4 code to appear?

The most common causes are a fault in the hybrid battery module, poor electrical connections, corroded wiring, or a malfunctioning Battery Energy Control Module (BECM).

Can I drive my Buick with code P1BF4?

Driving with this code is not recommended, as it may lead to further damage to the hybrid battery system or cause the vehicle to enter a reduced power mode.

How is code P1BF4 diagnosed?

A technician will use a scan tool to retrieve freeze frame data, inspect the hybrid battery connections and wiring, and test the affected circuit for proper voltage.

What repairs can fix the P1BF4 code?

Repairs may include replacing damaged wiring, repairing or replacing the hybrid battery module, or reprogramming the Battery Energy Control Module.

Is the P1BF4 code covered under warranty?

Hybrid battery-related issues may be covered under your vehicleâ€™s hybrid system warranty, so check with your dealer for warranty details.

How much does it cost to repair the P1BF4 code?

Repair costs can vary widely, ranging from $200 for wiring repairs to over $1,000 if the hybrid battery module needs replacement.

Will clearing the code fix the problem?

Clearing the code will temporarily remove the warning, but the underlying issue must be addressed to prevent the code from returning.

Can a low 12-volt battery cause the P1BF4 code?

While unlikely, a weak 12-volt battery can sometimes affect hybrid system diagnostics, so itâ€™s worth testing the 12-volt system as part of troubleshooting.