Engine-CodesGeneric – P066B

P066B Code - Cylinder 1 Glow Plug Control Circuit High Voltage

Quick Answer

The diagnostic trouble code P066B indicates a problem with the glow plug control circuit in cylinder 1 of the vehicle's engine. Common causes include Faulty glow plug in cylinder 1, Wiring issues in the glow plug control circuit, Corrosion or poor connection in the glow plug system. 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 indicates Cylinder 1 Glow Plug Control Circuit High Voltage.
Common causes
Common causes include Faulty glow plug in cylinder 1, Wiring issues in the glow plug control circuit, Corrosion or poor connection in the glow plug system.
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.
Table of contents Created and updated by William Orellana on Aug 19, 2024
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Code P066B Description

The diagnostic trouble code P066B indicates a problem with the glow plug control circuit in cylinder 1 of the vehicle's engine. Glow plugs are essential components in diesel engines that aid in starting the engine by heating the combustion chamber during cold weather conditions. When the control circuit for the glow plug in cylinder 1 is experiencing high voltage, it could lead to issues with starting the engine, reduced fuel efficiency, rough idling, and potential damage to the engine over time. This code typically triggers the Check Engine Light on the dashboard, alerting the driver to the underlying problem.

OBDII Code P066B - Cylinder 1 Glow Plug Control Circuit High Voltage
P066B Code - Cylinder 1 Glow Plug Control Circuit High Voltage

Common Causes of P066B

  1. Faulty glow plug in cylinder 1
  2. Wiring issues in the glow plug control circuit
  3. Corrosion or poor connection in the glow plug system
  4. Issues with the glow plug control module
  5. Engine control module (ECM) malfunction

Symptoms of P066B

  1. Check Engine Light is illuminated
  2. Difficulty starting the engine, especially in cold weather
  3. Reduced fuel efficiency
  4. Rough idling or misfiring
  5. Engine performance issues, such as lack of power or acceleration

How to Fix P066B

  1. Diagnose the specific issue by using a diagnostic scanner to retrieve the trouble code and pinpoint the exact cause of the high voltage in the glow plug control circuit.
  2. Inspect the wiring and connections related to the glow plug in cylinder 1 for any damage or corrosion. Repair or replace as necessary.
  3. Test the glow plug itself to ensure it is functioning correctly. Replace if faulty.
  4. Check the glow plug control module and ECM for any malfunctions. Repair or replace if needed.
  5. Clear the trouble code from the ECM memory and test the vehicle to ensure the issue has been resolved.

Cost to Fix P066B

The cost of repairing a cylinder 1 glow plug control circuit high voltage issue can vary depending on the specific cause of the problem and the make and model of the vehicle. On average, the parts for this repair can range from $50 to $200, while labor costs may add another $100 to $300. Overall, the total repair cost could be between $150 and $500. It's recommended to consult with a certified mechanic or auto repair shop for a more accurate estimate based on the individual circumstances.

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Code P066B Information for Specific Makes

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 P066B Code

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