AutoCodes – Generic – P1B55

P1B55 Code - Hybrid/Electric Vehicle Battery 38 Circuit Low 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: P1B55 indicates Hybrid/Electric Vehicle Battery 38 Circuit Low 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.

Save to My Repairs My Repairs

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

Code Popularity 1,092

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 09, 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 P1B55 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 P1B55 - Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage - AutoCodes.com — P1B55 Code - Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1B55?

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

How to Fix the DTC P1B55?

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 P1B55 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 P1B55 code?

Need more information on how to fix the P1B55 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1B55 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1B55 Buick — Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage
P1B55 Cadillac — Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage
P1B55 Chevrolet — Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage
P1B55 GMC — Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage
P1B55 Saturn — Hybrid/Electric Vehicle Battery 38 Circuit Low 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 P1B55 Code

1. What are the common symptoms of OBDII code P1B55 (Hybrid/Electric Vehicle Battery 38 Circuit Low Voltage)?

- Common symptoms include reduced fuel efficiency, loss of power, and potential difficulty starting the vehicle.

2. What are some possible causes of OBDII code P1B55?

- Possible causes may include a faulty hybrid/electric vehicle battery, damaged wiring or connectors in the battery circuit, or issues with the battery management system.

3. How can I diagnose OBDII code P1B55 related to low voltage in the hybrid/electric vehicle battery circuit?

- Diagnosing this code may require using a scan tool to check for specific voltage levels in the battery circuit and inspecting the battery and related components for any visible damage or corrosion.

4. Are there any safety precautions to consider when working on the hybrid/electric vehicle battery circuit?

- Yes, it is important to disconnect the high-voltage system properly before working on the battery circuit to prevent any risk of electrical shock or injury.

5. Can I reset OBDII code P1B55 on my own, or do I need to take the vehicle to a professional mechanic?

- It is recommended to have a professional mechanic diagnose and repair the underlying issue causing the code, as simply resetting the code may not fix the problem and could lead to further issues.

6. What are some repair tips for addressing OBDII code P1B55 in a hybrid or electric vehicle?

- Repair tips may include checking and cleaning the battery terminals, inspecting the battery wiring for any damage, and ensuring proper connection and voltage levels in the battery circuit.

7. How critical is it to address OBDII code P1B55 promptly in a hybrid or electric vehicle?

- It is important to address this code promptly to prevent further damage to the battery system and ensure the safe and efficient operation of the vehicle.

8. Can extreme weather conditions affect the occurrence of OBDII code P1B55 related to low voltage in the hybrid/electric vehicle battery circuit?

- Yes, extreme temperatures can impact the performance of the battery system and potentially trigger the low voltage code, so it is important to monitor the battery in such conditions.

9. Is it possible for DIY enthusiasts to troubleshoot and repair OBDII code P1B55 in a hybrid or electric vehicle?

- While some basic troubleshooting steps can be taken, diagnosing and repairing the underlying issue causing the code may require specialized knowledge and tools best handled by a trained professional.

10. Are there any recalls or technical service bulletins related to OBDII code P1B55 in hybrid or electric vehicles?

- It is recommended to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins specifically addressing issues related to this OBDII code.