AutoCodes – GMC – P1B0B GMC

P1B0B GMC Code - Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage

Quick Answer

The power inverter module, often referred to as the drive motor generator power inverter module, contains two motor control modules. Common causes include Faulty Drive Motor 1 Control Module Hybrid/EV Battery, Drive Motor 1 Control Module Hybrid/EV Battery harness is open or shorted, Drive Motor 1 Control Module Hybrid/EV Battery 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: P1B0B GMC indicates Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage.
Common causes: Common causes include Faulty Drive Motor 1 Control Module Hybrid/EV Battery, Drive Motor 1 Control Module Hybrid/EV Battery harness is open or shorted, Drive Motor 1 Control Module Hybrid/EV Battery 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 930

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 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1B0B GMC Description

The power inverter module, often referred to as the drive motor generator power inverter module, contains two motor control modules. Each motor control module measures hybrid battery high voltage with several internal sensors. The motor control modules test for loss of isolation between either the high-voltage positive circuit or high-voltage negative circuit and vehicle chassis. The motor control modules test for isolation when the high-voltage contactor relays are closed. The hybrid powertrain control module 2 only tests the hybrid battery assembly for high-voltage loss of isolation when the high-voltage contactor relays are open.
Motor control module loss of isolation is detected through the use of two high-impedance resistors and voltage measuring circuitry. The two resistors are connected in series between the high- voltage positive and high-voltage negative circuits. The centre connection of the two resistors is also connected to vehicle chassis. The motor control module then measures the voltage drop across one of the resistors. Without a loss of isolation, the motor control module should measure about half of the high voltage potential. This is referred to as mid-pack voltage. The Mid-pack voltage value is then doubled by the software and displayed on a scan tool as Motor 1 Isolation Voltage or Motor 2 Isolation Voltage. When a loss of isolation is present, the motor isolation voltage display will indicate voltage that is more or less than actual hybrid battery high voltage. The motor control module monitors the loss of isolation voltage measuring circuitry for correct operation.

OBDII Code P1B0B GMC - Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage - AutoCodes.com — P1B0B GMC Code - Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1B0B GMC?

Faulty Drive Motor 1 Control Module Hybrid/EV Battery
Drive Motor 1 Control Module Hybrid/EV Battery harness is open or shorted
Drive Motor 1 Control Module Hybrid/EV Battery circuit poor electrical connection

How to Fix the DTC P1B0B 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 P1B0B 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.

Need more information about the P1B0B GMC code?

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Need Help with the Code?

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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 P1B0B GMC Code

1. What are common symptoms of OBDII code P1B0B in a GMC vehicle?

- Common symptoms include reduced hybrid/EV system performance, decreased fuel efficiency, and potential illumination of the check engine light.

2. What could cause the Drive Motor 1 Control Module Hybrid/EV Battery Voltage Isolation Sensing Circuit 2 Low Voltage issue?

- Possible causes may include a faulty drive motor control module, damaged wiring or connectors, or issues with the battery voltage isolation sensing circuit.

3. How can I diagnose the source of the low voltage issue related to the drive motor control module?

- Use a multimeter to test the voltage levels at various points in the circuit, inspect the wiring and connectors for damage, and check for any loose connections or corrosion.

4. Are there any safety precautions to keep in mind when dealing with this OBDII code?

- It is important to work on the vehicle in a well-ventilated area, wear appropriate safety gear, and disconnect the hybrid/EV battery before attempting any diagnosis or repairs.

5. Can I continue driving my GMC with the P1B0B code present?

- It is not recommended to continue driving the vehicle with this code active, as it can lead to further damage to the hybrid/EV system and negatively impact overall performance.

6. What are some possible repair tips for resolving the Drive Motor 1 Control Module low voltage issue?

- Start by checking and repairing any damaged wiring or connectors, resetting the fault codes, and performing a thorough inspection of the drive motor control module.

7. Will resetting the OBDII code P1B0B make it go away permanently?

- Resetting the code may temporarily clear the warning light, but if the underlying issue is not addressed, the code is likely to reappear once the system detects the problem again.

8. How can a professional mechanic help in diagnosing and repairing the Drive Motor 1 Control Module issue?

- A mechanic can use specialized diagnostic tools to pinpoint the exact cause of the low voltage issue, perform component testing, and provide expert repairs to ensure proper functionality.

9. Is it possible to prevent the recurrence of the P1B0B code in the future?

- Regular maintenance of the hybrid/EV system, checking for any signs of wear or damage, and addressing any related issues promptly can help prevent the reoccurrence of this code.

10. Can a DIY enthusiast with automotive knowledge tackle the repair of the Drive Motor 1 Control Module low voltage problem?

- While some basic troubleshooting steps can be attempted by DIY enthusiasts, it is recommended to seek professional help for accurate diagnosis and proper repair of complex hybrid/EV system issues.