Error Code P066C : What It Means & What To Do?

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You are more likely to experience P066C error code if the Glow plug control module, Glow plug, Glow plug relay, Glow plug wiring harness is damaged. Glow plug preheats the cylinder before the engine starts. If one of the cylinder functions ineffectively, P066C code will be set by PCM.

High compression is used by diesel engine to start piston movement. As there is no spark, to increase compression, increase the cylinder temperature. Each cylinder has glow plugs to increase this, which is threaded into the cylinder head. If the voltage is correctly applied, it will glow bright red and helps to increase the temperature. When the level is reached, voltage is stopped and it returns to normal state.

What causes this problem with the Cylinder 2 Glow Plug Control Circuit Low?

• Defective glow plug/s.
• Glow plug control circuit has opening or shorted.
• Damaged glow plug connector.
• Flawed glow plug timer.

1. Power Control Module - A faulty or damaged PCM can be one of the primary reasons for this error code. Get them replaced instantly.
2. Engine Control Module - Find the right ECM for your vehicle from Parts Avatar at best prices online.
3. Glow Plug - If the glow plug is damaged or broken it won’t shine brightly. Get them component replaced with new one.
4. Glow Plug Relay - If the relay is not connected properly there can be an opening or shorted circuit. Visually inspect the component and repair them.
5. Glow Plug Control Module - Any damage or fault parts in the entire module can disturb the functioning of the system. Fix the part which causes this error code.
6. Glow plug wiring harness - If there are any oil leaks in the wiring joints, they have to be cleaned immediately.

Our main motive is to achieve customer satisfaction and that’s why we will help you to diagnose P066C code by mentioning some major symptoms below:

Common Symptoms

• More black smoke from exhaust.
• Issues with engine drivability.
• Engine starts with delay.
• Decreased fuel efficiency.
• Codes related to Engine misfire may be stored.

Learn the ways with which you can correct this trouble code:

• Changing Glow Plugs.

Parts Avatar Canada is here to solve all your issues related to car parts. We have stocked a wide range of best priced Power Control Module, Engine Control Module, Glow Plug, Glow Plug Relay, Glow Plug Control Module, Glow plug wiring harness and a lot more to help you out in fixing your car.

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

• A diagnostic scanner, a reliable source of vehicle information, and a DVOM is needed to diagnose P066c code. If you find a reliable TSB it can help you with proper diagnosis as it has information of the vehicle make and model and other error codes.
• Also, you will be needing diagnostic flowcharts, connector face views, connector pinout charts, wiring diagrams, module locations, and component testing processes to diagnose the P066C code.
• Connect the scanner to the diagnostic port of vehicle once you inspect the glow plug and its wires and connectors. Recover the codes and freeze the data. See if the code appears after test driving. Either the PCM will enter readiness mode, or the code will be set, if this happens continue with diagnosis. If not, there can be an irregular connection. You have to worsen the condition before diagnosing.
• One best way is to remove the glow plugs and test the voltage. If they glow bright red, they are good, if not test it with DVOM. Make sure not to burn yourself while carrying out the test.
• If they function normally, activate them with the help of scanner and test the battery voltage at the connector. If there is no voltage, test the glow plug timer/ controller for power supply. Test fuses, relays with loaded circuit as specified by manufacturer. The fuse which appears to be functional will direct you to wrong path.
• If both fuse and relay function properly, check the output voltage at the glow plug timer or PCM. If voltage is present, then there can be an open or shorted circuit where the circuit can be simply replaced.
• Sometimes you may think P066C code is caused by glow plug but it can also be due to variations in the control circuit which results in error code.
• One common error is trying to diagnose the wrong cylinder. Make sure you diagnose the right cylinder before proceeding with the process.