AutoCodes – GMC – P1B05 GMC

P1B05 GMC 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 GMC 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 1,821

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

What does this mean?

What are the Possible Causes of the DTC P1B05 GMC?

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 GMC?

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 GMC 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 GMC Code

1. What does the OBDII code P1B05 mean on a GMC vehicle?

P1B05 indicates an issue with the Drive Motor 1 Control Module High Voltage System Interlock Circuit, which monitors the integrity of the high-voltage system in hybrid or electric vehicles.

2. What are the common symptoms of a P1B05 code?

Symptoms may include the illumination of the check engine light, reduced vehicle performance, the inability to start the vehicle, or warnings related to the high-voltage system.

3. What causes the P1B05 code to appear?

Common causes include a damaged or disconnected high-voltage interlock circuit, faulty wiring or connectors, a malfunctioning drive motor control module, or an internal high-voltage system fault.

4. Can I continue driving with a P1B05 code?

It is not recommended to drive with a P1B05 code, as it could indicate a serious issue with the high-voltage system, which might pose safety risks or lead to further damage.

5. How is the P1B05 code diagnosed?

A technician will typically inspect the high-voltage interlock circuit, check for damaged wiring or connectors, and use a diagnostic scanner to monitor system data and pinpoint the fault.

6. What repairs are typically needed to fix a P1B05 code?

Repairs may include replacing damaged wiring, reconnecting loose high-voltage interlock connectors, repairing or replacing the drive motor control module, or addressing internal high-voltage faults.

7. How much does it cost to fix a P1B05 code on a GMC vehicle?

The cost varies depending on the severity of the issue, but it can range from $200 for simple wiring repairs to over $1,000 if the drive motor control module needs replacement.

8. Is the P1B05 code specific to GMC vehicles?

While P1B05 is most commonly associated with GMC hybrid or electric vehicles, it can also appear on other brands that use similar high-voltage systems.

9. Can a P1B05 code reset itself?

The code may reset temporarily if the issue is intermittent, but it will likely return unless the underlying problem is fixed.

10. Do I need special tools to diagnose or repair a P1B05 code?

Yes, diagnosing and repairing this code often requires specialized tools, such as a high-voltage-safe diagnostic scanner and insulated equipment for handling high-voltage components.