AutoCodes – Saturn – P0B77 Saturn

P0B77 Saturn Code - Hybrid/Electric Vehicle Battery 13 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: P0B77 Saturn indicates Hybrid/Electric Vehicle Battery 13 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.

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Code Popularity 982

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 P0B77 Saturn 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 P0B77 Saturn - Hybrid/Electric Vehicle Battery 13 Circuit - AutoCodes.com — P0B77 Saturn Code - Hybrid/Electric Vehicle Battery 13 Circuit

What does this mean?

What are the Possible Causes of the DTC P0B77 Saturn?

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

How to Fix the DTC P0B77 Saturn?

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 P0B77 Saturn 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 P0B77 Saturn Code

1. What does the OBDII code P0B77 mean on a Saturn?

P0B77 indicates an issue with the Hybrid/Electric Vehicle Battery 13 Circuit, which typically refers to a problem with the electrical circuit associated with the 13th battery block in the hybrid or electric vehicleâ€™s battery pack.

2. What are the common symptoms of a P0B77 code?

Symptoms may include a check engine light, reduced hybrid or electric vehicle performance, decreased fuel efficiency, and possible failure to enter EV mode.

3. What causes the P0B77 code to appear?

The code can be triggered by a faulty battery module, issues with wiring or connectors in the circuit, a defective battery management system (BMS), or corrosion or damage to the battery terminals.

4. Can I drive my Saturn with a P0B77 code active?

It is not recommended to drive the vehicle for extended periods as it may lead to further damage to the hybrid battery system or reduced performance.

5. How is the P0B77 code diagnosed?

A technician will use a scan tool to retrieve the code, inspect the battery packâ€™s 13th circuit for voltage irregularities, check wiring and connectors, and test the battery management system.

6. How can I fix the P0B77 code on my Saturn?

Repairs may include replacing the faulty battery module, repairing or replacing damaged wiring or connectors, cleaning corroded terminals, or reprogramming the battery management system.

7. How much does it cost to repair a P0B77 code?

Costs vary widely depending on the issue, ranging from $100 to repair wiring to over $1,000 if the battery module needs replacement.

8. Can a weak 12-volt battery cause the P0B77 code?

While unlikely, a weak 12-volt battery can sometimes cause communication issues within the hybrid system, which could indirectly trigger the code.

9. How do I prevent the P0B77 code from recurring?

Regular maintenance of the hybrid battery system, inspecting and cleaning connectors, and addressing any early signs of corrosion or damage can help prevent the code from recurring.

10. Does the P0B77 code mean my hybrid battery needs replacement?

Not always. The code may indicate an issue with a single battery block or its associated circuitry, which can sometimes be repaired without replacing the entire battery pack.