AutoCodes – Generic – P1B7C

P1B7C Code - Hybrid/Electric Vehicle Battery 51 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: P1B7C indicates Hybrid/Electric Vehicle Battery 51 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 1,040

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 P1B7C 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 P1B7C - Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage - AutoCodes.com — P1B7C Code - Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1B7C?

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

How to Fix the DTC P1B7C?

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 P1B7C 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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Information for Specific Makes

P1B7C Buick — Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage
P1B7C Cadillac — Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage
P1B7C Chevrolet — Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage
P1B7C GMC — Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage
P1B7C Saturn — Hybrid/Electric Vehicle Battery 51 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 P1B7C Code

1. What are the common symptoms of OBDII code P1B7C (Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage)?

- Common symptoms include reduced hybrid system performance, decreased fuel efficiency, and potential difficulty starting the vehicle.

2. What can cause the OBDII code P1B7C to trigger?

- This code is typically triggered by a low voltage condition in the hybrid/electric vehicle battery pack, often due to battery degradation, faulty battery cells, or issues with the battery management system.

3. How serious is the OBDII code P1B7C (Hybrid/Electric Vehicle Battery 51 Circuit Low Voltage)?

- This code should be addressed promptly to prevent further damage to the hybrid/electric vehicle battery system and ensure optimal vehicle performance.

4. Can I continue driving my vehicle with the OBDII code P1B7C active?

- It is not recommended to continue driving the vehicle with this code active, as it can lead to further damage to the battery system and potentially result in a sudden loss of power while driving.

5. What are some DIY repair tips for addressing OBDII code P1B7C?

- DIY repair options may include checking the battery connections for corrosion, ensuring the battery cooling system is functioning properly, and inspecting the battery for physical damage or leaks.

6. How can I diagnose the root cause of OBDII code P1B7C?

- Diagnosing the root cause may involve using a diagnostic scan tool to monitor battery voltage levels, conducting a battery load test, and inspecting the battery management system for any faults or malfunctions.

7. Is it safe to reset the OBDII code P1B7C without addressing the underlying issue?

- Resetting the code without addressing the underlying low voltage issue may temporarily turn off the check engine light, but the problem will likely persist and could lead to more serious battery issues in the future.

8. Can extreme weather conditions affect the likelihood of OBDII code P1B7C being triggered?

- Yes, extreme temperatures can impact the performance of hybrid/electric vehicle batteries and increase the risk of triggering code P1B7C due to voltage fluctuations.

9. How much does it typically cost to repair OBDII code P1B7C?

- The cost of repair can vary depending on the specific cause of the low voltage condition, but it may involve battery replacement, repairs to the battery management system, or other related components.

10. Are there any preventive maintenance steps to help avoid OBDII code P1B7C in hybrid/electric vehicles?

- Regularly monitoring the battery's health, following manufacturer-recommended maintenance schedules, and avoiding deep discharges of the battery can help prevent issues that may trigger code P1B7C.