AutoCodes – GMC – P101C GMC

P101C GMC Code - Glow Plug Control Module Temperature Sensor 2 Circuit High 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: P101C GMC indicates Glow Plug Control Module Temperature Sensor 2 Circuit High 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 448

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 Oct 01, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P101C GMC 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 P101C GMC - Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage - AutoCodes.com — P101C GMC Code - Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P101C GMC?

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 P101C 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 P101C 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 P101C GMC code?

Need more information on how to fix the P101C GMC code? Get Access to Factory Service Manuals

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Information for Specific GMC Models

P101C 2014 GMC Sierra — Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage
P101C 2015 GMC Sierra — Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage
P101C 2016 GMC Sierra — Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage
P101C 2017 GMC Sierra — Glow Plug Control Module Temperature Sensor 2 Circuit High Voltage
P101C 2018 GMC Sierra — Glow Plug Control Module Temperature Sensor 2 Circuit High 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 P101C GMC Code

1. What are the common symptoms of OBDII code P101C GMC?

- Common symptoms include check engine light illumination, rough engine idling, decreased fuel efficiency, and difficulty starting the vehicle.

2. What does the OBDII code P101C GMC indicate?

- The code indicates a high voltage condition in the Glow Plug Control Module Temperature Sensor 2 circuit.

3. What are the possible causes of OBDII code P101C GMC?

- Possible causes include a faulty glow plug control module, damaged wiring or connectors, a defective temperature sensor, or a malfunctioning powertrain control module (PCM).

4. How can I diagnose the cause of OBDII code P101C GMC?

- Diagnosing the cause may involve visually inspecting wiring and connectors, testing the glow plug control module and temperature sensor, and using a scan tool to gather data from the PCM.

5. Can I still drive my vehicle with OBDII code P101C GMC present?

- It is not recommended to drive the vehicle with this code present, as it can lead to poor engine performance and potential damage if left unresolved.

6. How do I repair OBDII code P101C GMC?

- Repairing the issue may involve replacing the glow plug control module, repairing or replacing damaged wiring, replacing the temperature sensor, or reprogramming the PCM.

7. Is it safe to reset the check engine light after resolving OBDII code P101C GMC?

- Yes, it is safe to reset the check engine light after resolving the issue. However, if the problem persists, the light may illuminate again.

8. Can extreme weather conditions affect the Glow Plug Control Module Temperature Sensor 2 circuit?

- Yes, extreme weather conditions can affect the sensor's performance, leading to potential high voltage readings and triggering OBDII code P101C GMC.

9. How important is it to address OBDII code P101C GMC promptly?

- It is important to address the code promptly to prevent further damage to the vehicle's engine and ensure optimal performance.

10. Are there any preventive maintenance tips to avoid OBDII code P101C GMC in the future?

- Regularly inspecting and maintaining the glow plug control module, temperature sensor, and related components can help prevent the recurrence of OBDII code P101C GMC.