P066F - OBD Trouble Code

Diesel engines utilize high compression as an alternative of spark to start piston movement. As there is no spark involved, cylinder temperature must be raised to improve compression. Glow plugs are used in individual cylinder to achieve this increase. Often confused with spark plugs, a glow plug for each separate cylinder is threaded into the cylinder head. Battery voltage is applied to the glow plug element through glow plug timer also known as a glow plug controller / module. When voltage is properly applied to the glow plug, it will exactly glow red hot and help in growing cylinder temperature. Once cylinder temperature reaches the preferred level, voltage is limited by the control unit and the glow plug proceeds to its normal state.

What causes this problem with the Cylinder 3 Glow Plug Control Circuit High?

• Defective glow plugs.
• Glow plug control circuit is open or shorted.
• Glow plug connector is damaged.
• Glow plug timer is loose.

1. Power Control Module - Check the PCM for any faults or damages. If you come across any, replace them immediately.
2. Engine Control Module - ECM has to function properly in order to avoid this error. Get the damaged part replaced immediately.
3. Glow Plug - If the glow plug light is low, then the component can be faulty. Replace the defective part as preferred.
4. Glow Plug Relay - Any damages in the relay can affect the glow plugs. Replace the damaged part immediately.
5. Glow Plug Control Module - This defective component has to be replaced with the right replacement part in order to avoid the P066F error code.
6. Glow plug wiring Harness - Look for leaks around the wiring joints. If you find any, clear them off or replace with new one.

Willing to know some common symptoms of OBD Code P066F? Your wish is our demand. Have a look at them below:

Common Symptoms

• Black smoke coming from exhaust.
• Issues with engine drivability.
• Engine start is delayed.
• Fuel efficiency is less.
• Codes related to engine misfire is stored.

It is very important to fix the fault code P066F. So here are some ways with which you can correct this issue:

• Replacing glow plug component.

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of Power Control Module, Engine Control Module, Glow Plug, Glow Plug Relay, Glow Plug Control Module, Glow plug wiring harness and many more. Now all your problems would vanish within no time.

If you want to easily diagnose this fault code, then all you have to do is to follow the steps which are mentioned below:

• Use a diagnostic scanner, a reliable source of vehicle information, and DVOM to perform correct diagnosis. Search for apt TSB that matches your vehicle model, make, stored code to perform diagnosis. Also, you can use diagnostic flow charts, wiring diagrams, connector face views, connector pinout charts, component locations, and component testing procedures to diagnose the error code P066F.
• You can connect the scanner to the diagnostic port once you check the glow plug/ wiring/ connectors. Recover all codes and freeze frame data. Test drive to see if codes recover. If the code resets then continue the diagnosis. You have to worsen the condition to perform careful diagnosis.
• Best way is to apply battery voltage by removing the glow plugs. Bright red glow shows it’s is good, if not test the glow plugs with DVOM. Make sure not to burn yourself while testing.
• If the glow plugs are in good condition, activate them and test for battery voltage at the connector. If no voltage is found, you have to test the glow plug timer / controller. Test the fuse and relays while the circuit is loaded. It may appear to function properly, but will lead to wrong path.
• If both the fuses and relays appear functional, test the output voltage with DVOM. If the voltage is low there can be an opening or shorted circuit which is simple to replace.
• It is sometimes assumed that a P066E cannot be the reason for a defective glow plug as it’s is a control circuit code. Sometimes , a bad glow plug will cause a difference in the control circuit that results in just such a code.
• Before you attempt to diagnose the cylinder, make sure that you are proceeding with the right cylinder.

Common Mistakes When Diagnosing the P066F Code

• Broken Glow plug control module.
• Broken Glow plug.
• Broken Glow plug relay.
• Broken Glow plug wiring harness.