AutoCodes – Buick – P1E99 Buick

P1E99 Buick Code - Hybrid/EV Battery Interface Control Module 2 5 V Reference Circuit

Quick Answer

The drive motor battery contains 288 cells. Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface Control Module circuit poor electrical connection. 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: P1E99 Buick indicates Hybrid/EV Battery Interface Control Module 2 5 V Reference Circuit.
Common causes: Common causes include Faulty Hybrid/EV Battery Interface Control Module, Hybrid/EV Battery Interface Control Module harness is open or shorted, Hybrid/EV Battery Interface Control Module circuit poor electrical connection.
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 815

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 Apr 24, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1E99 Buick Description

The drive motor battery contains 288 cells. Groups of three cells are welded together in parallel. There are a total of 96 cell groups in the drive motor battery assembly. These cell groups are electrically connected in-series. Each individual cell group is rated at 3.7 volts, for a nominal system voltage of 355 volts 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 cell groups. Voltage sense lines are attached to each individual cell group, and these sense lines terminate at a connector located on the top surface of the battery section. A serviceable voltage sense harness joins this connector to a drive motor battery high-voltage interface control module, also located on the top surface of the battery section. The drive motor battery high-voltage interface control module encodes the voltage reading and transmits it to the battery energy control module through the battery control harness. There is one drive motor battery high-voltage interface control module located on battery sections one and two, and two drive motor battery high-voltage interface control modules associated with battery section three. The drive motor battery high-voltage interface control module, voltage sense harnesses, battery control 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 P1E99 Buick - Hybrid/EV Battery Interface Control Module 2 5 V Reference Circuit - AutoCodes.com — P1E99 Buick Code - Hybrid/EV Battery Interface Control Module 2 5 V Reference Circuit

What does this mean?

What are the Possible Causes of the DTC P1E99 Buick?

Faulty Hybrid/EV Battery Interface Control Module
Hybrid/EV Battery Interface Control Module harness is open or shorted
Hybrid/EV Battery Interface Control Module circuit poor electrical connection

How to Fix the DTC P1E99 Buick?

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 P1E99 Buick 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 P1E99 Buick Code

1. What does the OBDII code P1E99 mean on a Buick?

P1E99 indicates an issue with the Hybrid/EV Battery Interface Control Module 2 5V reference circuit, which is crucial for voltage regulation and communication within the hybrid or electric vehicle system.

2. What are the common symptoms of the P1E99 code?

Symptoms may include the check engine light turning on, reduced hybrid/EV system performance, decreased fuel efficiency, or the vehicle entering a limp mode.

3. What causes the P1E99 code to appear?

Common causes include a faulty Hybrid/EV Battery Interface Control Module, damaged or corroded wiring, poor electrical connections, or an internal issue with the 5V reference circuit.

4. Can I drive my Buick with the P1E99 code?

While the vehicle may still be drivable, it could experience reduced performance or efficiency. It's recommended to address the issue promptly to avoid further damage to the hybrid/EV system.

5. How do I diagnose the P1E99 code?

Diagnosis involves using a scan tool to read live data, inspecting wiring and connectors for damage, and testing the 5V reference circuit for proper voltage and continuity.

6. How can the P1E99 code be fixed?

Repairs may include replacing the Hybrid/EV Battery Interface Control Module, repairing or replacing damaged wiring, or cleaning and securing electrical connections in the 5V reference circuit.

7. What tools do I need to troubleshoot the P1E99 code?

Youâ€™ll need an OBDII scanner capable of reading hybrid/EV-specific codes, a multimeter for testing voltage, and possibly wiring diagrams for your specific Buick model.

8. Is the P1E99 code specific to Buick hybrid vehicles?

Yes, this code typically applies to Buick hybrid or electric vehicles equipped with a Hybrid/EV Battery Interface Control Module.

9. How much does it cost to fix the P1E99 code?

Repair costs can vary widely, ranging from $100 for simple wiring repairs to over $1,000 if the control module needs replacement.

10. Can a weak 12V battery cause the P1E99 code?

While unlikely, a weak 12V battery can cause voltage irregularities that may lead to hybrid/EV system issues. Itâ€™s a good idea to test the 12V battery as part of the diagnostic process.