P066B 2018 GMC Sierra Code - Cylinder 1 Glow Plug Control Circuit High Voltage
Quick Answer
The P066B diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a problem with the Cylinder 1 Glow Plug Control Circuit High Voltage. Common causes include Faulty glow plug control module, Wiring issues such as a short or open circuit, Defective glow plug in cylinder 1. 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
- P066B 2018 GMC Sierra indicates Cylinder 1 Glow Plug Control Circuit High Voltage.
- Common causes
- Common causes include Faulty glow plug control module, Wiring issues such as a short or open circuit, Defective glow plug in cylinder 1.
- 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 P066B 2018 GMC Sierra Description
The P066B diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a problem with the Cylinder 1 Glow Plug Control Circuit High Voltage. Glow plugs are essential components in diesel engines, as they help to heat the combustion chamber for easier starting in cold weather. When the engine is cold, the glow plug control module sends a signal to the glow plugs to heat up. In the case of this code, the control circuit for the glow plug in cylinder 1 is experiencing high voltage, which can lead to various issues.
Common Causes of P066B 2018 GMC Sierra
- Faulty glow plug control module
- Wiring issues such as a short or open circuit
- Defective glow plug in cylinder 1
- ECM malfunction
- Corrosion or poor connections in the glow plug circuit
Symptoms of P066B 2018 GMC Sierra
- Hard starting, especially in cold weather
- Rough idling or engine vibration
- Misfires or hesitation during acceleration
- Decreased fuel efficiency
- Engine stalling
How to Fix P066B 2018 GMC Sierra
- Begin by diagnosing the specific cause of the high voltage in the glow plug control circuit, using a multimeter to test the voltage at various points.
- Inspect the wiring harness and connectors for any signs of damage, corrosion, or loose connections. Repair or replace as needed.
- Test the glow plug in cylinder 1 to ensure it is functioning properly. Replace if necessary.
- Check the glow plug control module for proper operation. Replace if it is found to be faulty.
- Clear the DTC with a scan tool after completing the repairs and test the vehicle to ensure the issue has been resolved.
Cost to Fix P066B 2018 GMC Sierra
The typical repair costs for addressing a P066B code in a 2018 GMC Sierra can vary depending on the specific cause of the issue. Parts such as a new glow plug control module or glow plug, as well as labor costs for diagnosis and repair, can range from $200 to $500 or more. It's important to note that labor rates at auto repair shops can vary, with hourly rates typically falling between $80 and $150. Additional costs may apply if other components need to be replaced or if further diagnostics are required. For a more accurate estimate, it is recommended to consult with a local auto repair shop.
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