AutoCodes – Generic – P0B40

P0B40 Code - Hybrid/Electric Vehicle Battery 2 Circuit

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: P0B40 indicates Hybrid/Electric Vehicle Battery 2 Circuit.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 3,168

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 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0B40 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 P0B40 - Hybrid/Electric Vehicle Battery 2 Circuit - AutoCodes.com — P0B40 Code - Hybrid/Electric Vehicle Battery 2 Circuit

What does this mean?

What are the Possible Causes of the DTC P0B40?

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

How to Fix the DTC P0B40?

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 P0B40 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.

Need more information about the P0B40 code?

Need more information on how to fix the P0B40 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0B40 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0B40 Buick — Hybrid/Electric Vehicle Battery 2 Circuit
P0B40 Cadillac — Hybrid/Electric Vehicle Battery 2 Circuit
P0B40 Chevrolet — Hybrid/Electric Vehicle Battery 2 Circuit
P0B40 GMC — Hybrid/Electric Vehicle Battery 2 Circuit
P0B40 Saturn — Hybrid/Electric Vehicle Battery 2 Circuit

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 P0B40 Code

1. What does the OBDII code P0B40 mean?

P0B40 indicates an issue with the Hybrid/Electric Vehicle Battery 2 Circuit, typically related to a fault in the wiring, connectors, or internal battery monitoring system.

2. What are the common symptoms of a P0B40 code?

Symptoms may include the hybrid system warning light, reduced fuel efficiency, limited power output, or the vehicle operating in a reduced performance mode.

3. What causes the P0B40 code to appear?

Common causes include damaged or corroded wiring, poor electrical connections, a faulty battery sensor, or internal issues with the hybrid battery pack.

4. Can I drive my car with a P0B40 code?

Driving with this code is not recommended as it may lead to further damage to the hybrid system, reduced performance, or potential safety issues.

5. How is the P0B40 code diagnosed?

A technician will use an OBDII scanner to confirm the code, inspect the battery circuit for damage, and test the voltage and continuity of the associated wiring and components.

6. How do I fix the P0B40 code?

Repairs may include repairing or replacing damaged wiring, cleaning or reconnecting loose connectors, or replacing the affected battery module or sensor.

7. Is the P0B40 code specific to certain car models?

No, the P0B40 code is a generic OBDII code applicable to hybrid and electric vehicles across various manufacturers, though the specific repair steps may vary.

8. What tools are needed to repair a P0B40 code?

Essential tools include an OBDII scanner, a multimeter for electrical testing, and potentially specialized tools for accessing and servicing the hybrid battery.

9. How much does it cost to fix the P0B40 code?

Repair costs vary depending on the issue but can range from $100 for simple wiring repairs to several thousand dollars if the hybrid battery needs replacement.

10. Can a P0B40 code be caused by a low hybrid battery charge?

No, the code typically points to a circuit issue, not a low charge. However, a prolonged low charge can sometimes exacerbate related problems.