With HFM and PMS control systems, it is no longer necessary to adjust the engine idle speed and carbon monoxide content. The system controls itself and accumulates detected faults in memory. A Mercedes workshop can identify faults using a reader and rectify them in a targeted manner. One malfunction is not necessarily visibly detected due to the deterioration of the vehicle's driving characteristics. Therefore, it is advisable to visit a service workshop after driving a certain distance.
The contents of the fault memory are retained even when the battery is disconnected. Faults stored in the memory are automatically erased if they no longer occur during approximately 20 consecutive trips. Faults stored in the memory can be manually erased using the fault reader.
When carrying out repairs on the fuel injection system, the rules for keeping the fuel system clean and the safety instructions for the ignition system must be followed.