AutoCodes – Cadillac – P0B79 Cadillac

P0B79 Cadillac Code - Hybrid/Electric Vehicle Battery 13 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: P0B79 Cadillac indicates Hybrid/Electric Vehicle Battery 13 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.

Save to My Repairs My Repairs

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

Code Popularity 966

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
Add Comment

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

Code P0B79 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 P0B79 Cadillac - Hybrid/Electric Vehicle Battery 13 Circuit Low Voltage - AutoCodes.com — P0B79 Cadillac Code - Hybrid/Electric Vehicle Battery 13 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P0B79 Cadillac?

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

How to Fix the DTC P0B79 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 P0B79 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.

Need more information about the P0B79 Cadillac code?

Need more information on how to fix the P0B79 Cadillac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0B79 Cadillac code diagnosed by a professional: Find a repair shop in your area

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 P0B79 Cadillac Code

What does the OBDII code P0B79 mean for a Cadillac?

P0B79 indicates "Hybrid/Electric Vehicle Battery 13 Circuit Low Voltage," meaning the vehicle's control module has detected a low voltage issue in the specific battery circuit labeled 13.

What are the common symptoms of code P0B79 in a Cadillac?

Symptoms may include reduced hybrid performance, a lit check engine light, decreased fuel efficiency, or the vehicle entering limp mode.

What causes the P0B79 code in a Cadillac?

Common causes include a faulty battery cell, damaged wiring or connectors in the battery circuit, a malfunctioning battery energy control module, or corrosion in the circuit.

Can I still drive my Cadillac with the P0B79 code?

Driving with this code is not recommended, as it can lead to further damage to the hybrid system and may leave you stranded if the battery performance deteriorates further.

How is the P0B79 code diagnosed?

A technician will use an OBDII scanner to confirm the code, inspect the hybrid battery and its circuits for damage, and test the voltage readings for circuit 13.

What repairs are commonly needed to fix the P0B79 code?

Repairs may include replacing a faulty battery cell, repairing or replacing damaged wiring or connectors, cleaning corroded terminals, or reprogramming the battery energy control module.

Can a weak 12-volt battery cause the P0B79 code?

While the 12-volt battery is separate from the hybrid battery system, issues with the 12-volt battery can sometimes affect diagnostics and should be checked as part of the troubleshooting process.

How much does it cost to fix the P0B79 code in a Cadillac?

Repair costs can vary widely, from $100 for minor wiring repairs to several thousand dollars if a hybrid battery replacement is required.

Can I reset the P0B79 code myself?

You can clear the code with an OBDII scanner, but if the underlying issue isnâ€™t fixed, the code will likely return, and ignoring it could cause further damage.

Is the P0B79 code covered under warranty for my Cadillac?

Hybrid battery components may be covered under a specific hybrid system warranty, which often exceeds the standard warranty. Check with your dealership for details.