AutoCodes – Cadillac – P1E81 Cadillac

P1E81 Cadillac Code - Hybrid/Electric Vehicle Battery 86 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: P1E81 Cadillac indicates Hybrid/Electric Vehicle Battery 86 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 961

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
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Code P1E81 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 P1E81 Cadillac - Hybrid/Electric Vehicle Battery 86 Circuit - AutoCodes.com — P1E81 Cadillac Code - Hybrid/Electric Vehicle Battery 86 Circuit

What does this mean?

What are the Possible Causes of the DTC P1E81 Cadillac?

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

How to Fix the DTC P1E81 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 P1E81 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 P1E81 Cadillac Code

1. What does the OBDII code P1E81 mean on a Cadillac?

P1E81 indicates an issue with the Hybrid/Electric Vehicle Battery 86 Circuit, typically related to the battery pack's voltage or communication.

2. What are the common symptoms of code P1E81 on a Cadillac?

Symptoms include reduced engine performance, warning lights on the dashboard, limited hybrid functionality, or the vehicle entering limp mode.

3. What causes the P1E81 code on a Cadillac?

Common causes include faulty battery wiring, a malfunctioning battery control module, corroded connectors, or internal battery pack issues.

4. Can I drive my Cadillac with a P1E81 code?

Driving with code P1E81 is not recommended, as it could cause further damage or lead to sudden performance loss, especially in hybrid or electric modes.

5. How do I diagnose the P1E81 code on my Cadillac?

Diagnosing this code involves scanning for additional codes, inspecting the battery wiring and connectors, and testing the battery control module for proper operation.

6. How much does it cost to fix a P1E81 code?

The repair cost varies depending on the issue but can range from $200 for wiring repairs to over $1,000 if the battery control module or pack needs replacement.

7. Can a weak 12V battery trigger the P1E81 code on a Cadillac?

A weak or failing 12V battery can sometimes cause communication errors, but P1E81 typically points to a high-voltage battery issue.

8. Is the P1E81 code specific to Cadillac vehicles?

No, while this code is common on Cadillac hybrids and electric vehicles, it may also appear on other GM brands with similar hybrid systems.

9. What tools are needed to repair a P1E81 code?

Repairing this code may require an OBDII scanner, multimeter, and specific GM diagnostic tools to test the hybrid battery and control systems.

10. Can a software update fix the P1E81 code?

In some cases, a software update for the battery control module may resolve the issue, but physical repairs are often required for wiring or hardware problems.