BMW DTC P066B – Cylinder 1 Glow Plug Control Circuit High
DTC P066B meaning on BMW
DTC P066B is a diagnostic trouble code that indicates an issue with the Cylinder 1 Glow Plug Control Circuit on a BMW vehicle. The code specifically points to a high voltage condition in the control circuit of the glow plug for cylinder 1.
BMW DTC P066B symptoms
Symptoms of DTC P066B on a BMW may include:
- Check Engine Light illuminated
- Engine misfires or runs rough
- Reduced engine performance
- Difficulty starting the engine, especially in cold conditions
BMW DTC P066B causes
Common causes of DTC P066B on a BMW include:
- Faulty glow plug for cylinder 1
- Wiring issues in the glow plug control circuit
- Defective glow plug control module
- Corrosion or poor connections in the circuit
BMW DTC P066B seriousness
While DTC P066B may not cause immediate drivability issues, it is important to address this code promptly to prevent potential long-term damage to the engine and emissions system. Ignoring the issue can lead to decreased fuel efficiency and increased emissions.
How to diagnose DTC P066B on BMW
To diagnose DTC P066B on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault code and freeze frame data
- Inspect the glow plug for cylinder 1 and its wiring for any visible damage or corrosion
- Check the glow plug control module for proper operation
- Perform a continuity test on the glow plug circuit to identify any open or short circuits
How to fix DTC P066B on BMW
To fix DTC P066B on a BMW, you can consider the following actions:
- Replace the faulty glow plug for cylinder 1
- Repair or replace any damaged wiring in the glow plug control circuit
- Replace the glow plug control module if necessary
- Clean any corrosion from the connections in the circuit
How to erase DTC P066B on BMW
To erase DTC P066B on a BMW, you can use a diagnostic scanner to clear the fault code from the vehicle’s memory. After addressing the underlying issue causing the code, clearing the code will reset the Check Engine Light and verify that the problem has been resolved.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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