U0103

U0103

Communication, Tiptronic control unit

NOTE: Internal function test completed.

Diagnostic conditions
The Tiptronic control unit initially tests internal function sequences after wake-up. 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