P06C5 GMC Code - Cylinder 1 Glow Plug Incorrect
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #1 glow plug, Cylinder #1 glow plug harness is open or shorted, Cylinder #1 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
- P06C5 GMC indicates Cylinder 1 Glow Plug Incorrect.
- Common causes
- Common causes include Faulty cylinder #1 glow plug, Cylinder #1 glow plug harness is open or shorted, Cylinder #1 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 P06C5 GMC 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. A Diagnostic Trouble Code (DTC) will be set if the Glow Plug resistance is not within a calibrated range.
What are the Possible Causes of the DTC P06C5 GMC?
- Faulty cylinder #1 glow plug
- Cylinder #1 glow plug harness is open or shorted
- Cylinder #1 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P06C5 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 P06C5 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 P06C5 GMC code?
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Need Help with the Code?
Get the P06C5 GMC code diagnosed by a professional: Find a repair shop in your area
Information for Specific GMC Models
- P06C5 2014 GMC Sierra — Cylinder 1 Glow Plug Incorrect
- P06C5 2015 GMC Sierra — Cylinder 1 Glow Plug Incorrect
- P06C5 2016 GMC Sierra — Cylinder 1 Glow Plug Incorrect
- P06C5 2017 GMC Sierra — Cylinder 1 Glow Plug Incorrect
- P06C5 2018 GMC Sierra — Cylinder 1 Glow Plug Incorrect
Frequently Asked Questions about P06C5 GMC Code
1. What does the OBDII code P06C5 mean on a GMC vehicle?
P06C5 indicates "Cylinder 1 Glow Plug Incorrect," meaning the glow plug in cylinder 1 is malfunctioning or not operating as expected.
2. What are the common symptoms of the P06C5 code?
Symptoms may include difficulty starting the engine in cold weather, reduced engine performance, a glowing check engine light, and increased emissions.
3. What causes the P06C5 code to appear?
Common causes include a faulty glow plug in cylinder 1, damaged glow plug wiring, a malfunctioning glow plug control module, or corrosion at the electrical connections.
4. Can I still drive my GMC vehicle with the P06C5 code?
While the vehicle may still run, driving with this code can lead to poor cold-weather performance and potential long-term engine damage. It’s best to address it promptly.
5. How can a faulty glow plug cause problems?
A faulty glow plug can hinder the diesel engine's ability to start and operate efficiently in cold temperatures, as it helps preheat the air in the cylinder for combustion.
6. How do you diagnose the P06C5 code?
Diagnosis typically involves scanning for codes, inspecting the glow plug and its wiring, testing the glow plug's resistance, and checking the glow plug control module for faults.
7. How is the P06C5 code fixed?
Repairs may involve replacing the faulty glow plug, repairing damaged wiring, cleaning corroded connections, or replacing the glow plug control module if necessary.
8. What tools are needed to diagnose and repair the P06C5 code?
Basic tools include an OBDII scanner, a multimeter to test resistance, and appropriate tools for accessing and replacing the glow plug.
9. How much does it cost to fix the P06C5 code on a GMC?
Repair costs vary but typically range from $100 to $300, depending on whether the glow plug, wiring, or control module needs replacement.
10. Can a P06C5 code clear itself after repairs?
The code may clear automatically after the issue is resolved, but in some cases, you may need to manually reset it using an OBDII scanner.
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