AutoCodes – Buick – P1B81 Buick

P1B81 Buick Code - Hybrid/Electric Vehicle Battery 53 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: P1B81 Buick indicates Hybrid/Electric Vehicle Battery 53 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 849

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 P1B81 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 P1B81 Buick - Hybrid/Electric Vehicle Battery 53 Circuit Performance - AutoCodes.com — P1B81 Buick Code - Hybrid/Electric Vehicle Battery 53 Circuit Performance

What does this mean?

What are the Possible Causes of the DTC P1B81 Buick?

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

How to Fix the DTC P1B81 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 P1B81 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 P1B81 Buick Code

1. What does the OBDII code P1B81 mean for a Buick?

P1B81 indicates a performance issue in the Hybrid/Electric Vehicle Battery 53 circuit, which could point to problems with the battery, wiring, or related control systems.

2. What are the common symptoms of the P1B81 code on a Buick?

Symptoms may include reduced hybrid or electric performance, warning lights on the dashboard, poor fuel economy, or limited EV mode functionality.

3. What causes the P1B81 code to appear?

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

4. Can I drive my Buick with the P1B81 code active?

While the vehicle may still be drivable, itâ€™s not recommended as continued driving could cause further damage to the hybrid system or affect overall performance.

5. How is the P1B81 code diagnosed?

Technicians will use a scan tool to confirm the code, inspect the battery and its circuitry for damage, and perform voltage and resistance tests on the affected circuit.

6. What repairs are needed to fix the P1B81 code?

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

7. How much does it cost to fix the P1B81 code?

Repair costs can vary widely, ranging from a few hundred dollars for wiring repairs to several thousand dollars if the hybrid battery needs replacement.

8. Can a weak 12-volt battery cause the P1B81 code?

While a weak 12-volt battery can cause electrical issues, the P1B81 code specifically relates to the high-voltage hybrid battery system and is unlikely to be caused by the 12-volt battery.

9. Does the P1B81 code always require battery replacement?

No, the code doesnâ€™t always mean the entire battery needs replacement. Sometimes the issue is with a single cell, wiring, or the control module.

10. How can I prevent the P1B81 code from recurring?

Regular maintenance of the hybrid system, ensuring clean and secure electrical connections, and addressing any warning signs promptly can help prevent this code from recurring.