P068D 2014 GMC Sierra Code - Cylinder 7 Glow Plug Control Circuit High Voltage
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #7 glow plug, Cylinder #7 glow plug harness is open or shorted, Cylinder #7 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
- P068D 2014 GMC Sierra indicates Cylinder 7 Glow Plug Control Circuit High Voltage.
- Common causes
- Common causes include Faulty cylinder #7 glow plug, Cylinder #7 glow plug harness is open or shorted, Cylinder #7 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.
Code P068D 2014 GMC Sierra Description
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.
What are the Possible Causes of the DTC P068D 2014 GMC Sierra?
- Faulty cylinder #7 glow plug
- Cylinder #7 glow plug harness is open or shorted
- Cylinder #7 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P068D 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 P068D 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 P068D 2014 GMC Sierra code?
Need more information on how to fix the P068D 2014 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P068D 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P068D 2014 GMC Sierra Code
What does the OBDII code P068D mean for a 2014 GMC Sierra?
P068D indicates a high voltage issue in the Cylinder 7 Glow Plug Control Circuit, which can affect the glow plug’s operation.
What are common symptoms of code P068D in a 2014 GMC Sierra?
Symptoms may include difficulty starting the engine in cold weather, rough idling, reduced fuel efficiency, and the check engine light turning on.
What causes the P068D code in a 2014 GMC Sierra?
Common causes include a faulty glow plug, damaged wiring or connectors in the glow plug circuit, or a malfunctioning glow plug control module.
Can driving with the P068D code damage my 2014 GMC Sierra?
Driving with this code may not immediately damage the vehicle, but prolonged operation could lead to starting issues and potential damage to the glow plug system.
How is the P068D code diagnosed?
A mechanic typically uses a scan tool to confirm the code, inspects the wiring and connectors, tests the glow plug, and checks the control module for faults.
How do you fix the P068D code on a 2014 GMC Sierra?
Repairing the code may involve replacing the faulty glow plug, repairing damaged wiring or connectors, or replacing the glow plug control module.
Can a weak battery cause the P068D code to appear?
Yes, a weak battery can result in insufficient voltage for the glow plug system, potentially triggering this code.
How much does it cost to repair the P068D code on a 2014 GMC Sierra?
Repair costs vary based on the issue but may range from $150 to $400 for parts and labor, depending on whether the glow plug, wiring, or control module needs replacement.
Can I reset the P068D code without fixing the problem?
While you can clear the code with a scan tool, the issue will likely return unless the underlying problem is resolved.
How can I prevent the P068D code from recurring?
Regular maintenance, including inspecting the glow plug system and addressing wiring issues promptly, can help prevent this code from recurring.
Discuss the causes and fixes for P068D 2014 GMC Sierra OBDII Code
Code P068D 2014 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.
