AutoCodes – Buick – P1B66 Buick

P1B66 Buick Code - Hybrid/Electric Vehicle Battery 44 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: P1B66 Buick indicates Hybrid/Electric Vehicle Battery 44 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 972

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 P1B66 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 P1B66 Buick - Hybrid/Electric Vehicle Battery 44 Circuit Performance - AutoCodes.com — P1B66 Buick Code - Hybrid/Electric Vehicle Battery 44 Circuit Performance

What does this mean?

What are the Possible Causes of the DTC P1B66 Buick?

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

How to Fix the DTC P1B66 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 P1B66 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 P1B66 Buick Code

What does the OBDII code P1B66 mean on a Buick?

The P1B66 code indicates an issue with the Hybrid/Electric Vehicle Battery 44 Circuit Performance, which refers to a problem with the battery or its associated circuitry in the hybrid or electric system.

What are the common symptoms of code P1B66 on a Buick?

Common symptoms include reduced hybrid or electric performance, warning lights on the dashboard, decreased fuel efficiency, and possible limited driving range.

What causes the P1B66 code on a Buick?

This code can be caused by faulty battery sensors, wiring issues, poor electrical connections, or a malfunctioning hybrid battery module.

Can I still drive my Buick if the P1B66 code is active?

You may be able to drive the vehicle, but itâ€™s not recommended as the hybrid system may operate at reduced efficiency or cause long-term damage to the battery system.

How is the P1B66 code diagnosed?

Technicians use a diagnostic scan tool to read the code and inspect the hybrid battery system, sensors, wiring, and connections for faults or irregularities.

What repairs are needed to fix the P1B66 code on a Buick?

Repairs may include replacing faulty battery sensors, repairing damaged wiring, or replacing the hybrid battery module if itâ€™s defective.

How much does it cost to repair the P1B66 code on a Buick?

Repair costs can vary widely, ranging from $100 for minor wiring repairs to over $2,000 for hybrid battery replacement, depending on the severity of the issue.

Can a weak 12V battery cause the P1B66 code?

While unlikely, a weak 12V battery can occasionally affect hybrid system diagnostics. Itâ€™s best to check both the 12V and hybrid batteries during troubleshooting.

How do I prevent the P1B66 code from recurring on my Buick?

Regular maintenance, ensuring proper battery charging, and inspecting connectors and wiring for damage can help prevent this code from reappearing.

Is the P1B66 code covered under warranty for a Buick?

If your Buick is still under warranty, particularly for the hybrid system, this code may be covered. Consult your vehicleâ€™s warranty details or contact your dealer for confirmation.