Self-diagnosis of the diesel heating device (Mercedes-Benz C-Class W202)

The electronically controlled diesel fuel system (EVE, ERE) performs diagnostics on its own and accumulates the detected faults in the fault memory. If a serious fault occurs, the EDS indicator on the instrument panel lights up. (EDS – Electronic Diesel Control). In a Mercedes workshop, faults can be interrogated using a reading device and purposefully eliminated. A fault does not necessarily arise due to poor driving characteristics of the car. Therefore, it is advisable to interrogate the accumulated faults at certain mileage intervals.

The contents of the fault memory are retained even if the battery is disconnected. Accumulated faults are automatically erased if they are no longer observed within approximately 20 consecutive trips. Faults that the device has stored can be cleared manually using the fault reader.