U0103

U0103

Communication, Tiptronic control unit

NOTE: Internal function test completed.

Diagnostic conditions
The Tiptronic control unit initially tests internal function sequences after wakeup. If they are OK, all diagnosable outputs are then tested and any faults are stored.

Tiptronic control unit wake-up through:
- Event-induced CAN message
- "Ignition on"

Possible fault causes
- No power supply for Tiptronic control unit
- Tiptronic control unit is incorrectly coded
- Short circuit or open circuit in the CAN drive
- Tiptronic control unit faulty (in most cases the cause is not the Tiptronic control unit but incorrect coding.)
- DME control unit faulty

Fault effects
- Communication via the CAN drive is no longer possible
- No other control units are able to communicate with the Tiptronic control unit

Affected contacts on the Tiptronic control unit connector

Connector B
- 29 Power supply-terminal 15
- 30 Ground supply-terminal 31

Connector C
- 1 CAN drive low
- 2 CAN drive high

Affected contacts on the DME control unit connector

Connector B-CAN drive OUT
- 3 CAN drive low
- 4 CAN drive high

Connector D-CAN drive IN
- 36 CAN drive high
- 37 CAN drive low