AutoCodes – Cadillac – P0B9C Cadillac

P0B9C Cadillac 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 Cadillac 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 964

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

What does this mean?

What are the Possible Causes of the DTC P0B9C Cadillac?

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

How to Fix the DTC P0B9C Cadillac?

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 Cadillac 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 P0B9C Cadillac Code

1. What does the OBDII code P0B9C mean for a Cadillac?

P0B9C indicates a "Hybrid/Electric Vehicle Battery 20 Circuit Low Voltage," meaning there is a detected low voltage in the 20th battery module or circuit of the hybrid/electric battery system.

2. What are the common symptoms of code P0B9C in a Cadillac?

Symptoms include reduced fuel efficiency, diminished electric range, warning lights such as the check engine light or hybrid system light, and possible loss of power or performance.

3. What causes the P0B9C code to appear in a Cadillac?

Common causes include a faulty battery module, loose or corroded wiring connections, a malfunctioning battery management system, or issues with the hybrid control module.

4. Can I drive my Cadillac with the P0B9C code?

It is not recommended to drive the vehicle with this code active, as it may result in further damage to the hybrid system or cause performance and safety issues.

5. How is the P0B9C code diagnosed in a Cadillac?

A technician will use a scan tool to read the code, inspect the battery module and its wiring for damage or corrosion, and test the voltage of the affected circuit.

6. How do you fix the P0B9C code on a Cadillac?

Repairs may include replacing the faulty battery module, repairing or replacing damaged wiring, cleaning corroded connections, or reprogramming/updating the battery management system.

7. How much does it cost to fix the P0B9C code on a Cadillac?

The repair cost can vary widely, ranging from $100 to $500 for wiring repairs and up to several thousand dollars if the battery module needs to be replaced.

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

While unlikely, a weak 12-volt battery can sometimes cause hybrid system issues. Itâ€™s important to test and rule it out during diagnostics.

9. Does the P0B9C code mean the entire hybrid battery needs replacement?

Not necessarily. The issue may be isolated to the 20th battery module or its circuit, which can sometimes be repaired without replacing the entire battery pack.

10. How can I prevent the P0B9C code from occurring again?

Regular maintenance, ensuring battery connections are secure and corrosion-free, and addressing hybrid system issues promptly can help prevent this code from reoccurring.