Description of on Board Diagnostics

The self-check program integrated into the EDS control unit tests the electronic diesel system i.e. detects and stores system malfunctions. Intermittent malfunctions, which occur for longer than 4 seconds, are also stored.

For example, sensor malfunctions, with the exception of engine speed sensor, are stored into memory, as well as short circuits in the actuators and their input wiring. Through the use of an impulse counter at socket 4 of the 38-pole test connection (X11/4), the individual malfunctions can be recalled for evaluation. The proper diagnosis can be determined according to the indicated malfunction.