AutoCodes – GMC – P101B 2015 GMC Sierra

P101B 2015 GMC Sierra Code - Glow Plug Control Module Temperature Sensor 2 Circuit Low Voltage

Quick Answer

The Glow Plug Control Module (GPCM) has the ability to perform internal diagnostics for the temperature sensor circuit. Common causes include Faulty Glow Plug Control Module (GPCM), Glow Plug Control Module harness is open or shorted, Glow Plug Control 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: P101B 2015 GMC Sierra indicates Glow Plug Control Module Temperature Sensor 2 Circuit Low Voltage.
Common causes: Common causes include Faulty Glow Plug Control Module (GPCM), Glow Plug Control Module harness is open or shorted, Glow Plug Control 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 227

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Oct 01, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P101B 2015 GMC Sierra Description

The Glow Plug Control Module (GPCM) has the ability to perform internal diagnostics for the temperature sensor circuit. The GPCM monitors the internal temperature sensor voltage and if the voltage is less than 0.21 V or greater than 4.94 V. The GPCM will send a message to the Engine Control Module (ECM) to set the appropriate Diagnostic Trouble Code (DTC). A DTC is detected when one of the GPCM temperature sensors voltage falls outside the calibrated threshold for greater than 1.3 s.

OBDII Code P101B 2015 GMC Sierra - Glow Plug Control Module Temperature Sensor 2 Circuit Low Voltage - AutoCodes.com — P101B 2015 GMC Sierra Code - Glow Plug Control Module Temperature Sensor 2 Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P101B 2015 GMC Sierra?

Faulty Glow Plug Control Module (GPCM)
Glow Plug Control Module harness is open or shorted
Glow Plug Control Module circuit poor electrical connection

How to Fix the DTC P101B 2015 GMC Sierra?

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 P101B 2015 GMC Sierra 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 P101B 2015 GMC Sierra 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 P101B 2015 GMC Sierra Code

1. What does the OBDII code P101B mean on a 2015 GMC Sierra?

P101B indicates a "Glow Plug Control Module Temperature Sensor 2 Circuit Low Voltage," meaning the sensor is reporting a voltage below the expected range.

2. What are the common symptoms of the P101B code on a 2015 GMC Sierra?

Symptoms may include difficulty starting in cold weather, reduced engine performance, a check engine light, and possibly a rough idle.

3. What causes the P101B code to appear?

Common causes include a faulty temperature sensor, damaged wiring or connectors, short circuits, or issues with the glow plug control module.

4. Can I drive my 2015 GMC Sierra with the P101B code active?

While the truck may still be drivable, it might experience starting issues in cold weather and reduced performance. Prompt diagnosis and repair are recommended.

5. How do I diagnose the P101B code on a 2015 GMC Sierra?

Start by inspecting the temperature sensor wiring and connectors for damage or corrosion, then test the sensor itself and the glow plug control module for proper operation.

6. How do I fix the P101B code on my GMC Sierra?

Repairs may involve replacing the temperature sensor, repairing damaged wiring or connectors, or replacing the glow plug control module if itâ€™s faulty.

7. Is the temperature sensor the only possible issue causing P101B?

No, while the sensor is a common cause, wiring issues, connector problems, or a failing glow plug control module can also trigger the code.

8. How much does it cost to repair the P101B code on a 2015 GMC Sierra?

The repair cost depends on the issue but typically ranges from $100 to $300 for parts and labor, depending on whether the sensor or module needs replacement.

9. Can a bad battery cause the P101B code?

A weak or failing battery could contribute to electrical issues, but itâ€™s not a direct cause of P101B. Always ensure the battery is in good condition when diagnosing electrical faults.

10. Do I need specialized tools to fix the P101B code?

Basic tools like a multimeter for testing voltage and an OBDII scanner to clear the code are helpful. Advanced diagnostics may require more specialized tools.