What does P0507 fault code mean on UK cars? How to fix idle control system issues

The P0507 fault code indicates your car's idle air control system is running at higher RPMs than expected, commonly caused by air leaks after the throttle body, faulty IAC valves, or throttle control module issues. In UK models like the Vauxhall Astra or Ford Focus, this often requires checking for throttle body dirt, inspecting IAC valve circuits, and scanning for faulty sensors using OBD2 diagnostics.

Common fixes include:

1. Cleaning or replacing a dirty throttle body - common in high-mileage UK diesels
2. Testing and replacing faulty idle air control valves (found between the air intake and manifold)
3. Checking for vacuum leaks in hoses around the intake manifold
4. Resetting the ECU after repairs - many modern UK cars (like the Nissan Qashqai) require this

For accurate diagnosis, use a professional OBD2 scanner to check live data from the throttle position sensor and manifold absolute pressure sensor. The RAC recommends these steps before considering expensive PCM replacements.