Idle Air Control - Idle Speed Too Low

P0506

Idle Air Control - Idle Speed Too Low

Function
The idle air control (IAC) permits a stable and low idle speed. The idle air control (IAC) valve opens a bypass to the throttle valve. The size of the opening depends on the operation of the IAC valve. As the mass air flow (MAF) sensor senses this secondary air, the injection volume changes accordingly. The DME control module makes comparisons with the specified engine speed and corrects it accordingly.

Diagnosis conditions
- Start-up ended.
- Speed = 0 km/h.
- Throttle valve in idle position.
- Engine temperature [>] 60 °C.
- Intake air temperature [>] -10 °C.
- No fuel tank ventilation or tank ventilation diagnosis.
- No faults in speed signal, throttle position sensor, IAC valve, engine temperature, EVAP canister purge valve or tank ventilation system.

A fault is detected and stored in the memory after 15 sec. if the engine speed is too high by 200 rpm or too low by 100 rpm.

P0506-P0507:

Wiring Diagram







Diagnosis Procedure

DTC P0506







DTC P0507







1 Check IAC valve.

1. Connect and switch on Porsche System Tester 2.
2. In the "Drive links" menu, select and activate IAC valve.
3. A distinct clicking noise should be heard.