P0727

P0727
Rpm signal from ECm - Not present

Function:
The rpm signal is calculated by the ECm and transferred to the Tiptronic control module via a data lead (CAN bus). The rpm signal is required in order to determine the gear required in each case and, if necessary, to initiate shifting operations.
The "restricted driving program" is activated in the event of a faulty signal.

Diagnosis Conditions:
- Selector lever position "D"
- Transmission output speed > I 92 rpm




Wiring Diagram:




Diagnosis Procedure:



1 Check data lead from Tiptronic control module to ECm control unit for continuity.
1. Pull off Tiptronic control module connector.
2. Pull off ECm connector.
3. Connect ohmmeter to Tiptronic control module connector, pin 85 (or pin 86), and ECm control unit connector, pin 85 (or pin 86).

Indication: 0...5 ohm.

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

1 Check data lead from Tiptronic control module to ECm control unit for short circuit to ground.
1. Connect ohmmeter to Tiptronic control module connector, pin 85 (or pin 86), and ground.

Indication: infinite ohm.

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

1 Check data lead from Tiptronic control module to ECm control unit for short circuit to plus.
1. Switch on ignition.
2. Connect voltmeter to Tiptronic control module connector, pin 85 (or pin 86), and ground.

Indication: 0 Volt.

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