P066D 2015 GMC Sierra Code - Cylinder 2 Glow Plug Control Circuit High Voltage
Quick Answer
The diagnostic trouble code P066D for a 2015 GMC Sierra indicates an issue with the Cylinder 2 Glow Plug Control Circuit having a high voltage. Common causes include Faulty Glow Plug: A defective glow plug in Cylinder 2 could be the cause of the high voltage in the control circuit, Short Circuit: A short circuit in the wiring or connectors associated with the glow plug control circuit can lead to high voltage readings, Glow Plug Control Module Failure: If the control module responsible for regulating the voltage to the glow plugs malfunctions, it can result in high voltage output. 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
- P066D 2015 GMC Sierra indicates Cylinder 2 Glow Plug Control Circuit High Voltage.
- Common causes
- Common causes include Faulty Glow Plug: A defective glow plug in Cylinder 2 could be the cause of the high voltage in the control circuit, Short Circuit: A short circuit in the wiring or connectors associated with the glow plug control circuit can lead to high voltage readings, Glow Plug Control Module Failure: If the control module responsible for regulating the voltage to the glow plugs malfunctions, it can result in high voltage output.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P066D 2015 GMC Sierra Description
The diagnostic trouble code P066D for a 2015 GMC Sierra indicates an issue with the Cylinder 2 Glow Plug Control Circuit having a high voltage. Glow plugs are crucial components in diesel engines, especially during cold starts when the engine needs assistance with combustion. The glow plug control module monitors and controls the voltage to the glow plugs to ensure proper ignition and efficient combustion.
Common Causes of P066D 2015 GMC Sierra
- Faulty Glow Plug: A defective glow plug in Cylinder 2 could be the cause of the high voltage in the control circuit.
- Short Circuit: A short circuit in the wiring or connectors associated with the glow plug control circuit can lead to high voltage readings.
- Glow Plug Control Module Failure: If the control module responsible for regulating the voltage to the glow plugs malfunctions, it can result in high voltage output.
- Electrical Issues: Any underlying electrical problems such as a damaged wire or poor connection can disrupt the glow plug control circuit's operation.
- PCM (Powertrain Control Module) Failure: A failure in the PCM, which controls various engine functions, including the glow plug system, can trigger this diagnostic trouble code.
Symptoms of P066D 2015 GMC Sierra
- Check Engine Light: The most common symptom associated with this diagnostic code is the illumination of the Check Engine Light on the vehicle's dashboard.
- Rough Idle: The engine may experience a rough idle or unstable RPMs due to the improper functioning of the glow plug in Cylinder 2.
- Hard Starting: Difficulty starting the engine, especially in cold weather, can be a symptom of malfunctioning glow plugs.
- Decreased Fuel Efficiency: A malfunctioning glow plug can lead to incomplete combustion, resulting in reduced fuel efficiency.
- Engine Misfires: High voltage in the glow plug control circuit can contribute to engine misfires, impacting overall performance.
How to Fix P066D 2015 GMC Sierra
- Diagnose the Issue: Use a diagnostic scan tool to confirm the P066D code and identify the specific glow plug control circuit causing the high voltage.
- Inspect Glow Plugs: Check the condition of the glow plugs in Cylinder 2 and replace any faulty plugs.
- Check Wiring and Connectors: Inspect the wiring harness and connectors associated with the glow plug control circuit for any damage or corrosion.
- Test Glow Plug Control Module: Test the functionality of the glow plug control module and replace it if necessary.
- Clear Codes and Test Drive: Clear the diagnostic trouble codes, reset the Check Engine Light, and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P066D 2015 GMC Sierra
The cost of repairing a Cylinder 2 Glow Plug Control Circuit High Voltage issue can vary depending on the extent of the damage, the need for replacement parts, and labor charges. On average, the repair cost for this problem ranges from $200 to $500, including parts and labor. However, prices can fluctuate based on the specific diagnosis time and labor rates at auto repair shops. It's recommended to obtain quotes from local mechanics to get a more accurate estimate for your vehicle.
Need more information about the P066D 2015 GMC Sierra code?
Need more information on how to fix the P066D 2015 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P066D 2015 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P066D 2015 GMC Sierra Code
No Frequently Asked Questions about P066D 2015 GMC Sierra Code found.
Discuss the causes and fixes for P066D 2015 GMC Sierra OBDII Code
Code P066D 2015 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.