AutoCodes – Generic – P1E77

P1E77 Code - Hybrid/Electric Vehicle Battery 76 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: P1E77 indicates Hybrid/Electric Vehicle Battery 76 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.

Save to My Repairs My Repairs

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

Code Popularity 1,280

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 14, 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 P1E77 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 P1E77 - Hybrid/Electric Vehicle Battery 76 Circuit - AutoCodes.com — P1E77 Code - Hybrid/Electric Vehicle Battery 76 Circuit

What does this mean?

What are the Possible Causes of the DTC P1E77?

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

How to Fix the DTC P1E77?

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 P1E77 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 P1E77 code?

Need more information on how to fix the P1E77 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1E77 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1E77 Buick — Hybrid/Electric Vehicle Battery 76 Circuit
P1E77 Cadillac — Hybrid/Electric Vehicle Battery 76 Circuit
P1E77 Chevrolet — Hybrid/Electric Vehicle Battery 76 Circuit
P1E77 GMC — Hybrid/Electric Vehicle Battery 76 Circuit
P1E77 Saturn — Hybrid/Electric Vehicle Battery 76 Circuit

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 P1E77 Code

1. What does the OBDII code P1E77 mean?

P1E77 indicates a problem with the Hybrid/Electric Vehicle Battery 76 Circuit, which typically involves a specific cell or circuit within the high-voltage battery system.

2. What are the common symptoms of a P1E77 code?

Symptoms may include reduced fuel efficiency, limited electric driving range, a check engine light, or a warning for the hybrid system.

3. What causes the P1E77 code to appear?

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

4. Can I still drive my car with a P1E77 code?

While the vehicle may remain operational, driving with this code could lead to further damage to the battery system and reduced performance. Itâ€™s best to address it promptly.

5. How is the P1E77 code diagnosed?

A technician will use a scan tool to read the code, check for additional fault codes, inspect the battery circuit for wiring or connector issues, and test the affected battery cell(s).

6. What repairs are typically required for a P1E77 code?

Repairs may include replacing a damaged battery cell, repairing or replacing wiring or connectors, or reprogramming the battery control module if needed.

7. Can a weak 12V battery trigger the P1E77 code?

While unlikely, a weak 12V battery can cause communication issues that might indirectly affect hybrid system diagnostics.

8. How much does it cost to fix the P1E77 code?

Repair costs vary depending on the specific issue, ranging from a few hundred dollars for minor wiring repairs to several thousand dollars for replacing a high-voltage battery module.

9. Is the P1E77 code covered under warranty?

If your vehicle is still under a hybrid or electric battery warranty, repairs related to this code may be covered. Check with your dealership or manufacturer.

10. Can I clear the P1E77 code without fixing the problem?

Clearing the code without resolving the underlying issue will only temporarily remove the warning, and the code is likely to return as soon as the fault is detected again.