AutoCodes – Generic – P1B77

P1B77 Code - Hybrid/Electric Vehicle Battery 49 Circuit High 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: P1B77 indicates Hybrid/Electric Vehicle Battery 49 Circuit High 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 20,508

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 12, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B77 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 P1B77 - Hybrid/Electric Vehicle Battery 49 Circuit High Voltage - AutoCodes.com — P1B77 Code - Hybrid/Electric Vehicle Battery 49 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1B77?

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

How to Fix the DTC P1B77?

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 P1B77 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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Information for Specific Makes

P1B77 Buick — Hybrid/Electric Vehicle Battery 49 Circuit High Voltage
P1B77 Cadillac — Hybrid/Electric Vehicle Battery 49 Circuit High Voltage
P1B77 Chevrolet — Hybrid/Electric Vehicle Battery 49 Circuit High Voltage
P1B77 GMC — Hybrid/Electric Vehicle Battery 49 Circuit High Voltage
P1B77 Saturn — Hybrid/Electric Vehicle Battery 49 Circuit High 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 P1B77 Code

1. What are the common symptoms of OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Common symptoms include the check engine light illuminating, reduced hybrid/electric vehicle performance, and potential issues with battery charging.

2. What are the possible causes of OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Possible causes include a malfunctioning battery pack, faulty battery management system, damaged high voltage wiring, or issues with the hybrid/electric vehicle's control module.

3. How can I diagnose OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Diagnosis typically involves using a diagnostic scanner to read the code, inspecting the high voltage wiring for damage, testing the battery pack and management system, and checking the control module for faults.

4. Is it safe to continue driving with OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- It is not recommended to continue driving with this code present, as it can indicate potentially dangerous high voltage issues that may impact the vehicle's performance and safety.

5. Can OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage be repaired at home?

- While basic inspections like checking for loose connections or damaged wiring can be done at home, diagnosing and repairing complex high voltage issues should be left to trained professionals due to safety concerns.

6. How much does it typically cost to repair OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- The cost of repairs can vary widely depending on the specific issue causing the code, but it may range from a few hundred to a few thousand dollars, especially if parts like the battery pack need to be replaced.

7. Are there any maintenance tips to prevent OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Regularly scheduled maintenance, such as checking and servicing the battery pack, monitoring the high voltage system, and following manufacturer recommendations, can help prevent issues that may trigger this code.

8. Can a faulty hybrid/electric vehicle battery cause OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Yes, a faulty battery pack or its management system can lead to high voltage circuit issues, triggering this specific OBDII code.

9. Will resetting the check engine light resolve OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- Simply resetting the check engine light will not fix the underlying issue causing the code. It is important to diagnose and repair the root cause to prevent the code from reoccurring.

10. How urgent is it to address OBDII code P1B77 Hybrid/Electric Vehicle Battery 49 Circuit High Voltage?

- It is recommended to address this code promptly to avoid potential safety hazards and prevent further damage to the hybrid/electric vehicle's high voltage system.