AutoCodes – Buick – P1B18 Buick

P1B18 Buick Code - Hybrid/Electric Vehicle Battery 27 Circuit High 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: P1B18 Buick indicates Hybrid/Electric Vehicle Battery 27 Circuit High 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 925

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 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B18 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 P1B18 Buick - Hybrid/Electric Vehicle Battery 27 Circuit High Voltage - AutoCodes.com — P1B18 Buick Code - Hybrid/Electric Vehicle Battery 27 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1B18 Buick?

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

How to Fix the DTC P1B18 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 P1B18 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 P1B18 Buick Code

1. What does the OBDII code P1B18 mean for a Buick?

P1B18 indicates an issue with the Hybrid/Electric Vehicle Battery 27 Circuit experiencing high voltage, which may signal a problem with the battery module or related wiring.

2. What are common symptoms of code P1B18 in a Buick?

Symptoms may include the hybrid system warning light, reduced fuel efficiency, limited vehicle performance, or the vehicle entering limp mode.

3. What causes the P1B18 code in a Buick?

Common causes include a faulty battery module, damaged or corroded wiring, a poor electrical connection, or a malfunctioning battery control module.

4. Can I continue driving my Buick with the P1B18 code?

Itâ€™s not recommended to drive for extended periods with this code as it could lead to further damage or limit the hybrid system's functionality.

5. How is the P1B18 code diagnosed in a Buick?

A technician will use a scan tool to confirm the code, inspect wiring and connections, and test the hybrid battery module and control circuit for abnormalities.

6. How do you fix the P1B18 code on a Buick?

Repairs may involve replacing the faulty battery module, repairing damaged wiring or connectors, or reprogramming/updating the battery control module.

7. Is the P1B18 code covered under warranty for my Buick?

Hybrid battery issues may be covered under the vehicle's hybrid system or emissions warranty; check with your dealership for specific coverage details.

8. Can a weak 12V battery cause the P1B18 code in a Buick?

While unlikely, a weak 12V battery can sometimes cause communication issues within the hybrid system, so it's worth checking as part of the diagnostic process.

9. What tools are needed to troubleshoot the P1B18 code on a Buick?

A diagnostic scan tool, a multimeter, and manufacturer-specific service information are typically needed to troubleshoot this code.

10. How much does it cost to fix the P1B18 code on a Buick?

Repair costs vary but could range from $200 to $1,500 or more, depending on whether the issue is with wiring, the battery module, or another hybrid system component.