AutoCodes – Generic – P0B9C

P0B9C Code - Hybrid/Electric Vehicle Battery 20 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: P0B9C indicates Hybrid/Electric Vehicle Battery 20 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 1,567

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 P0B9C 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 P0B9C - Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage - AutoCodes.com — P0B9C Code - Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0B9C?

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

How to Fix the DTC P0B9C?

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 P0B9C 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 P0B9C code?

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Need Help with the Code?

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Information for Specific Makes

P0B9C Buick — Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage
P0B9C Cadillac — Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage
P0B9C Chevrolet — Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage
P0B9C GMC — Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage
P0B9C Saturn — Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage

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 P0B9C Code

1. What does the OBDII code P0B9C mean?

The P0B9C code indicates that the voltage in the Hybrid/Electric Vehicle Battery 20 circuit is lower than expected, which can affect the vehicle's hybrid or electric system performance.

2. What are common symptoms of the P0B9C code?

Symptoms may include reduced fuel efficiency, limited hybrid or electric mode functionality, warning lights on the dashboard, and diminished overall vehicle performance.

3. What causes the P0B9C code to appear?

Common causes include a damaged or degraded battery cell, faulty wiring or connectors in the battery circuit, or a malfunctioning battery management system (BMS).

4. Can a weak 12-volt battery cause the P0B9C code?

While the 12-volt battery is separate from the high-voltage system, a weak 12-volt battery can sometimes lead to communication issues that trigger hybrid-related codes.

5. How is the P0B9C code diagnosed?

Diagnosis typically involves checking the battery voltage, inspecting wiring and connectors in the circuit, and using a scan tool to monitor the battery management system's data.

6. Can I drive with the P0B9C code active?

Itâ€™s not advisable to drive for extended periods with this code active, as it may lead to reduced performance or further damage to the hybrid or electric powertrain components.

7. How do you fix the P0B9C code?

Repairs may involve replacing or rebalancing the affected battery module, repairing damaged wiring or connectors, or recalibrating the battery management system.

8. How much does it cost to repair the P0B9C code?

Repair costs can range from $100 for minor wiring fixes to several thousand dollars if a battery module or the full battery pack needs replacement.

9. Can resetting the code fix the P0B9C issue?

Clearing the code may temporarily turn off the warning light, but it wonâ€™t fix the underlying issue. Proper diagnosis and repair are necessary.

10. Is the P0B9C code covered under warranty?

In many cases, hybrid or electric vehicle battery-related issues are covered under the manufacturerâ€™s warranty, especially if the vehicle is within the warranty period. Check your warranty terms for specifics.