P1715

P1710
Speed signal, front right - signal implausible.

P1715
Speed signal, front left - signal implausible.

Function:
The Tiptronic control module receives the speed signals of the two front wheels from the ABS control unit.
For locking in gears during curves the Tiptronic control module calculates the lateral acceleration from the vehicle speed and the speed difference between the front wheels.

Diagnosis Conditions:
- Speed > 60 km/m
- Overrun




Wiring Diagram:




Diagnosis Procedure:



1 Test speed signal with oscilloscope at Tiptronic control module connector.



1. Pull off Tiptronic control module connector.
2. Connect oscilloscope to Tiptronic control module connector pin 38 (or pin 39) in accordance with the manufacturer's instructions.
3. Jack up vehicle at the front.
4. Switch on ignition.
5. manually turn the front-right wheel or front-left wheel in driving direction.


2 Check wires from Tiptronic control module to ABS/TC control unit for continuity.

ABS/TC Control Unit Connector:

1. Pull off Tiptronic control module connector.
2. Pull off ABS control unit connector.
3. Connect ohmmeter to Tiptronic control module connector connector pin 38 (or pin 39) and ABS/TC control unit connector pin 25 (or pin 26).

Indication: 0...5 ohm.

If infinite ohm is indicated, check wiring harness for crushing and points of contact.

2 Check wires from Tiptronic control module to ABS/TC control unit for short circuit to ground.
1. Connect ohmmeter to Tiptronic control module connector pin 38 (or pin 39) and ground.

Indication: infinite ohm.

If 0.. .5 ohm is indicated, check wiring harness for crushing and chafing damage.

2 Check wiring control module to ABS/TC control unit for short circuit to plus.
1. Switch on ignition.
2. Connect voltmeter to Tiptronic control module connector pin 38 (or pin 39) and ground.

Indication: 0 Volt.

If battery voltage is indicated, check wiring harness for crushing and chafing damage.