P0685

P0685

Diagnostic information - DME (DFI)

Main relay on

NOTE: As soon as there is > 8 V voltage applied to DME control unit connector contact A34 (terminal 15) (ignition on), a check is made to establish whether the main relay has switched on (voltage > 6 V at contacts A3/A5/A6).

Diagnostic conditions
- Vehicle voltage > 8 V
- Ignition on

Possible fault causes
- Fuse in current distributor faulty
- DME main relay faulty
- Open circuit in line between fuse in power distributor and DME main relay (power supply for relay activation)
- Short circuit to ground or open circuit in line between DME main relay and DME control unit (DME power supply)
- Short circuit to B+ or open circuit in line between DME main relay and DME control unit (DME relay activation)