AutoCodes – Buick – P1B05 Buick

P1B05 Buick Code - Drive Motor 1 Control Module High Voltage System Interlock Circuit

Quick Answer

The high voltage interlock circuit is utilized to verify high voltage component integrity. Common causes include Faulty Drive Motor Generator Power Inverter Module, Drive Motor Generator Power Inverter Module harness is open or shorted, Drive Motor Generator Power Inverter 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: P1B05 Buick indicates Drive Motor 1 Control Module High Voltage System Interlock Circuit.
Common causes: Common causes include Faulty Drive Motor Generator Power Inverter Module, Drive Motor Generator Power Inverter Module harness is open or shorted, Drive Motor Generator Power Inverter 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 908

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 01, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B05 Buick Description

The high voltage interlock circuit is utilized to verify high voltage component integrity. High voltage interlock circuit is a circuit loop that passes through certain high voltage components. High voltage interlock circuit is used to determine if access to high voltage components is being attempted. The opening of these high voltage components causes the high voltage interlock circuit to open. The battery energy control module sources about 12 mA of current on the 5V high voltage interlock circuit loop. The battery energy control module monitors both the high voltage interlock source current circuit and the high voltage interlock return current circuit in order to detect circuit faults. Both motor control modules monitor the circuit for current in order to detect an open condition. When the battery energy control module and/or the motor control modules sense conditions such as a loss of high voltage interlock circuit current, the high voltage contactor relays are commanded open by the hybrid powertrain control module.

OBDII Code P1B05 Buick - Drive Motor 1 Control Module High Voltage System Interlock Circuit - AutoCodes.com — P1B05 Buick Code - Drive Motor 1 Control Module High Voltage System Interlock Circuit

What does this mean?

What are the Possible Causes of the DTC P1B05 Buick?

Faulty Drive Motor Generator Power Inverter Module
Drive Motor Generator Power Inverter Module harness is open or shorted
Drive Motor Generator Power Inverter Module circuit poor electrical connection

How to Fix the DTC P1B05 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 P1B05 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 P1B05 Buick Code

What does the OBDII code P1B05 mean for a Buick?

P1B05 indicates an issue with the high voltage interlock circuit in the Drive Motor 1 Control Module, which is part of the hybrid or electric powertrain system.

What are common symptoms of the P1B05 code on a Buick?

Symptoms may include reduced power or performance, warning lights such as the check engine light, and possible failure to start the vehicle.

What causes the P1B05 code to appear?

This code is often caused by a faulty high voltage interlock circuit, damaged wiring or connectors, or issues with the Drive Motor 1 Control Module itself.

Can I drive my Buick safely with the P1B05 code?

Driving with this code is not recommended, as it may lead to reduced performance and potential safety risks related to the high voltage system.

How is the P1B05 code diagnosed?

Technicians typically use a scan tool to confirm the code, inspect the high voltage interlock circuit, check for damaged wiring or loose connections, and test the Drive Motor 1 Control Module.

How can the P1B05 code be fixed?

Repairs may involve replacing damaged wiring or connectors, repairing the high voltage interlock circuit, or replacing the Drive Motor 1 Control Module if faulty.

What tools are needed to address the P1B05 code?

Repairing this code may require a diagnostic scan tool, multimeter for testing circuits, and appropriate safety gear for handling high voltage components.

Is the P1B05 code specific to hybrid or electric Buick models?

Yes, this code is typically associated with Buick models that have hybrid or electric drive systems.

Can a failing battery cause the P1B05 code?

While not the most common cause, issues with the high voltage battery or its connections may contribute to this code.

Should I attempt to fix the P1B05 code myself?

Due to the complexity and risks associated with high voltage systems, itâ€™s recommended to have a professional technician handle repairs for this code.