AutoCodes – Generic – P1B39

P1B39 Code - Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance

Quick Answer

The hybrid battery pack contains a total of 32 cell groups in the hybrid/EV battery pack assembly. Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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: P1B39 indicates Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance.
Common causes: Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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 1,076

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 P1B39 Description

The hybrid battery pack contains a total of 32 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 118 V DC. The battery cells are grouped together into two sections, each with 16 cell groups.
The battery energy control module monitors the voltage of the 32 battery cell groups. A voltage sense circuit is attached to each individual cell group. Each of these circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connectors the voltage sense circuits to the battery energy control module, located directly above the hybrid battery pack.
To ensure proper battery function and lengthen battery life, the battery energy control module balances the voltage of the cells so that each cells maintains the same voltage level. The battery energy control module uses internal voltage gates to transfer voltage from cells with a higher voltage level to those cells with a lower voltage level. To maintain a similar state of charge on the cell groups, the starter/generator control module monitors the cell voltages and determines which cells need energy removed in order to maintain the cells at a similar state of charge. A resistor wired in parallel with the cell and a transistor switch in series with the resistor internal to the battery energy control module. The starter/generator control module sends a command to the battery energy control module to begin cell balancing.

OBDII Code P1B39 - Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance - AutoCodes.com — P1B39 Code - Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance

What does this mean?

What are the Possible Causes of the DTC P1B39?

Faulty Battery Energy Control Module
Battery Energy Control Module harness is open or shorted
Battery Energy Control Module circuit poor electrical connection

How to Fix the DTC P1B39?

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 P1B39 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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Need Help with the Code?

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Information for Specific Makes

P1B39 Buick — Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance
P1B39 Cadillac — Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance
P1B39 Chevrolet — Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance
P1B39 GMC — Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance
P1B39 Saturn — Battery Energy Control Module Hybrid Battery Voltage Balance Processor 6 Performance

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 P1B39 Code

1. What does the OBDII code P1B39 mean?

P1B39 indicates a performance issue with Processor 6 of the Battery Energy Control Module, which monitors and balances the hybrid battery's voltage.

2. What are the common symptoms of code P1B39?

Symptoms may include reduced fuel efficiency, a lit check engine light, limited hybrid system performance, and potential warning messages on the dashboard.

3. What causes the P1B39 code to appear?

Common causes include a faulty hybrid battery cell, defective Battery Energy Control Module, poor electrical connections, or damaged wiring in the hybrid battery system.

4. Can I continue driving with code P1B39?

While it may be possible to drive temporarily, ignoring this code could lead to further hybrid system damage or reduced performance. Prompt diagnosis and repair are recommended.

5. How is P1B39 diagnosed?

A technician will use a scan tool to confirm the code, inspect the hybrid battery's voltage, check the Battery Energy Control Module, and examine wiring and connections for damage or corrosion.

6. What repairs are typically needed for code P1B39?

Repairs can include replacing defective hybrid battery cells, repairing damaged wiring, or replacing the Battery Energy Control Module if it is found to be faulty.

7. How much does it cost to fix the P1B39 code?

The repair cost varies depending on the issue but may range from $200 for wiring repairs to over $2,000 if the hybrid battery or control module needs replacement.

8. Can a weak hybrid battery cause the P1B39 code?

Yes, a weak or failing hybrid battery can lead to voltage imbalances and trigger the P1B39 code.

9. Is there a way to prevent the P1B39 code from occurring?

Regular maintenance of the hybrid system, including monitoring battery health and addressing issues early, can help prevent this code.

10. Can a software update fix the P1B39 code?

In some cases, a software update for the Battery Energy Control Module may resolve the issue, but this depends on the manufacturer and specific circumstances.