AutoCodes – Generic – P1B20

P1B20 Code - Hybrid/Electric Vehicle Battery 30 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: P1B20 indicates Hybrid/Electric Vehicle Battery 30 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.

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Code Popularity 1,976

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 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B20 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 P1B20 - Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage - AutoCodes.com — P1B20 Code - Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1B20?

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

How to Fix the DTC P1B20?

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 P1B20 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 P1B20 code?

Need more information on how to fix the P1B20 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1B20 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1B20 Buick — Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage
P1B20 Cadillac — Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage
P1B20 Chevrolet — Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage
P1B20 GMC — Hybrid/Electric Vehicle Battery 30 Circuit Low Voltage
P1B20 Saturn — Hybrid/Electric Vehicle Battery 30 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 P1B20 Code

1. What does the OBDII code P1B20 mean?

P1B20 indicates a low voltage condition in the Hybrid/Electric Vehicle Battery 30 circuit, which typically involves the high-voltage battery or its associated wiring and control systems.

2. What are the common symptoms of a P1B20 code?

Symptoms may include warning lights on the dashboard, reduced hybrid or EV performance, poor fuel efficiency, or the vehicle failing to switch into electric mode.

3. What causes the P1B20 code to appear?

Common causes include damaged wiring or connectors in the battery circuit, a malfunctioning battery control module, or issues within the high-voltage battery itself.

4. Can I still drive my vehicle with a P1B20 code?

Itâ€™s not recommended to drive the vehicle with this code, as it may lead to further damage or compromise the safety and performance of the hybrid or electric powertrain.

5. How is the P1B20 code diagnosed?

A technician will use a scan tool to verify the code, inspect the battery circuit for wiring issues, and test the high-voltage battery and its control module for proper operation.

6. What are potential repairs for a P1B20 code?

Repairs may include fixing or replacing damaged wiring, replacing the battery control module, or addressing faults in the high-voltage battery pack.

7. How much does it cost to repair a P1B20 code?

The repair cost can vary widely depending on the exact cause, ranging from $100 for minor wiring repairs to several thousand dollars if the high-voltage battery needs replacement.

8. Can a weak 12-volt battery cause a P1B20 code?

While the 12-volt battery plays a role in the vehicleâ€™s electrical system, this code is specific to the high-voltage battery circuit and is unlikely to be caused by the 12-volt battery.

9. Will resetting the code fix the problem?

Clearing the code without addressing the underlying issue will not fix the problem, and the code is likely to reappear.

10. Is the P1B20 code specific to certain vehicle brands?

While the code applies to hybrid and electric vehicles, the exact diagnostics and repair process may vary depending on the manufacturer. Always refer to the vehicleâ€™s service manual.