AutoCodes – Buick – P1B8B Buick

P1B8B Buick Code - Hybrid/Electric Vehicle Battery 56 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: P1B8B Buick indicates Hybrid/Electric Vehicle Battery 56 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 944

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 P1B8B 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 P1B8B Buick - Hybrid/Electric Vehicle Battery 56 Circuit Low Voltage - AutoCodes.com — P1B8B Buick Code - Hybrid/Electric Vehicle Battery 56 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1B8B Buick?

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

How to Fix the DTC P1B8B 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 P1B8B 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 P1B8B Buick Code

What does the OBDII code P1B8B mean for a Buick?

The P1B8B code indicates a low voltage issue in the Hybrid/Electric Vehicle Battery 56 Circuit, which is part of the high-voltage battery system.

What are the common symptoms of code P1B8B in a Buick?

Symptoms may include a check engine light, reduced hybrid performance, decreased fuel efficiency, or the vehicle operating in a failsafe or limp mode.

What causes the P1B8B code to appear on a Buick?

Common causes include a faulty hybrid battery cell, damaged wiring or connectors in the Battery 56 Circuit, or a malfunctioning battery control module.

Can I still drive my Buick with a P1B8B code?

Driving is possible but not recommended, as the vehicle may experience reduced performance, and prolonged use could cause further damage to the hybrid battery system.

How is the P1B8B code diagnosed?

A technician will use a scan tool to check for related codes, inspect the wiring and connectors, test the battery cell voltages, and evaluate the functionality of the battery control module.

What repairs are typically needed to fix the P1B8B code?

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

How much does it cost to fix the P1B8B code on a Buick?

The cost varies depending on the issue but can range from $200 to $1,000 or more, especially if the hybrid battery requires repair or replacement.

Can a P1B8B code be caused by a software issue?

Yes, in some cases, outdated or corrupted software in the battery control module may trigger this code, and a software update or reprogramming may resolve the issue.

How can I prevent the P1B8B code from recurring?

Regular maintenance, including inspecting the hybrid battery system and ensuring wiring and connectors are in good condition, can help prevent this code from recurring.

Is the P1B8B code covered under warranty for a Buick?

It may be covered under the hybrid or electric vehicle battery warranty, depending on the vehicle's age and mileage. Check with your dealership for warranty details.