AutoCodes – GMC – P066E 2014 GMC Sierra

P066E 2014 GMC Sierra Code - Cylinder 3 Glow Plug Control Circuit Low Voltage

Quick Answer

n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #3 glow plug, Cylinder #3 glow plug harness is open or shorted, Cylinder #3 glow plug 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: P066E 2014 GMC Sierra indicates Cylinder 3 Glow Plug Control Circuit Low Voltage.
Common causes: Common causes include Faulty cylinder #3 glow plug, Cylinder #3 glow plug harness is open or shorted, Cylinder #3 glow plug 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 207

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 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P066E 2014 GMC Sierra Description

n the diesel engine, air alone is compressed in the cylinder. Then, after the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition occurs, due to the heat of compression. Eight glow plugs are used as an aid to starting.
Control of the glow plugs is accomplished by the Glow Plug Control Module. The nominal voltage for the glow plugs is 5.4 volts. When the ignition is turned On, the Glow Plug Control Module applies 7.2 V for 2.2 s, then 5.7 V for 0.8 s, and then 5.4 V until 1200°C (2192°F) is reached. The maximum voltage of the system is 10 V. While the engine is running the voltage will vary between 4.7 - 10 V when in closed loop control to maintain a glow plug temperature that ranges from 1150° - 1180°C (2102° - 2156°F). The temperature and the power consumption are controlled between the Engine Control Module (ECM) and the Glow Plug Control Module within a wide range to suit the engine's pre-heating requirements. Each glow plug is energized individually. This capability yields more optimum heat times for the glow plugs, thus pre - glow times can be kept to a minimum for a short wait to crank times and maximum glow plug durability.

OBDII Code P066E 2014 GMC Sierra - Cylinder 3 Glow Plug Control Circuit Low Voltage - AutoCodes.com — P066E 2014 GMC Sierra Code - Cylinder 3 Glow Plug Control Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P066E 2014 GMC Sierra?

Faulty cylinder #3 glow plug
Cylinder #3 glow plug harness is open or shorted
Cylinder #3 glow plug circuit poor electrical connection
Faulty Glow Plug Control Module

How to Fix the DTC P066E 2014 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 P066E 2014 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 P066E 2014 GMC Sierra code?

Need more information on how to fix the P066E 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P066E 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 P066E 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code P066E on a 2014 GMC Sierra related to the Cylinder 3 Glow Plug Control Circuit Low Voltage?

- Common symptoms include rough idling, misfires, loss of power, and potential illumination of the check engine light.

2. What are the possible causes of the Cylinder 3 Glow Plug Control Circuit Low Voltage issue indicated by OBDII code P066E on a 2014 GMC Sierra?

- Possible causes include a faulty glow plug, damaged wiring or connectors, a defective glow plug control module, or issues with the engine control module.

3. How can I diagnose and repair the Cylinder 3 Glow Plug Control Circuit Low Voltage problem on my 2014 GMC Sierra triggering OBDII code P066E?

- To diagnose, check the glow plug resistance, inspect wiring for damage, and use a multimeter to test for voltage. Repair may involve replacing the faulty glow plug, fixing wiring issues, or replacing the control module.

4. Is it safe to continue driving my 2014 GMC Sierra with the Cylinder 3 Glow Plug Control Circuit Low Voltage issue causing OBDII code P066E?

- It is not recommended to drive the vehicle extensively with this issue, as it can lead to poor engine performance, increased emissions, and potential damage to other engine components.

5. Can a DIY enthusiast fix the Cylinder 3 Glow Plug Control Circuit Low Voltage problem indicated by OBDII code P066E on a 2014 GMC Sierra?

- Depending on the skill level and tools available, some DIY enthusiasts may be able to diagnose and repair this issue, but it is recommended to consult a professional mechanic for accurate diagnosis and proper repair.

6. How much does it typically cost to repair the Cylinder 3 Glow Plug Control Circuit Low Voltage issue causing OBDII code P066E on a 2014 GMC Sierra?

- The cost of repair can vary based on the exact cause of the issue, but it may range from $100 to $500 for parts and labor, depending on the extent of the problem.

7. Will resetting the OBDII code P066E on my 2014 GMC Sierra make the Cylinder 3 Glow Plug Control Circuit Low Voltage issue go away?

- Resetting the code may temporarily clear the check engine light, but it will not fix the underlying problem causing the Cylinder 3 Glow Plug Control Circuit Low Voltage issue.

8. Can a Cylinder 3 Glow Plug Control Circuit Low Voltage issue, as indicated by OBDII code P066E, affect the overall performance and fuel efficiency of a 2014 GMC Sierra?

- Yes, this issue can impact engine performance, leading to reduced fuel efficiency, rough running, and potential damage if left unresolved.

9. Are there any preventive maintenance steps I can take to avoid encountering the Cylinder 3 Glow Plug Control Circuit Low Voltage issue triggering OBDII code P066E on my 2014 GMC Sierra?

- Regularly inspecting and maintaining the glow plugs, wiring, and control modules can help prevent issues related to the Cylinder 3 Glow Plug Control Circuit from occurring.

10. How long does it typically take for a mechanic to diagnose and repair the Cylinder 3 Glow Plug Control Circuit Low Voltage issue causing OBDII code P066E on a 2014 GMC Sierra?

- The diagnosis and repair process can vary in time, but it may take a few hours to a full day, depending on the complexity of the issue and the availability of parts.