P0721
Fault code P0721Output shaft speed inductive pickup [Output Speed Sensor Circuit Range/Performance]
The PSM signal is used for further calculations.
NOTE: Rough gear shifts while vehicle is stationary. In the event of two faults (output shaft speed inductive pickup and PSM fault), reverse gear can be engaged while the vehicle is in motion. The output shaft speed is calculated using the input shaft speed.
NOTE: The ignition must be switched off and then switched on again in order to display an error message in the instrument cluster.
Diagnostic conditions
- Voltage greater than 10.2 V and less than 15.5 V
- Ignition on
- Internal Tiptronic control module function test was completed successfully
- Engine runs without malfunctions, engine speed '> 400 rpm'
- Brake not actuated
- PSM speed > 10 km/h
- No electrical faults in output shaft speed inductive pickup
- No faults stored for CAN drive
- No PSM faults
No difference in speed between PSM signal and output shaft speed inductive pickup > 25% for 250 msec. The fault is stored in memory after it occurs 40 times.
Possible causes of fault
- 'Implausible signal', mechanical damage in sensor wheel or inductive pickup
- 'Implausible signal', inductive pickup faulty
- 'Implausible signal', Tiptronic control module faulty
Affected pins
Tiptronic control module plug:
- Pin '-'
Diagnosis/troubleshooting G 0210
Wiring diagram of output shaft speed inductive pickup
1 - Tiptronic control module
2a - Pickup (sensor) wheel
2b - Inductive pickup
38 - Pin (38)
50 - Pin (50)
I - Current flow
Data on 'output shaft speed inductive pickup'
Internal resistance cannot be measured.
- Sensor type: Hall-IC
- Max. current: 65 mA
- Number of pulses: 24 per output shaft revolution
NOTE:
Replacing control module: Before replacing the 'Tiptronic control module', the ground connections, power supply and plug connections on the control module must be checked. Please observe the coding of the control module. After the test drive, read out the fault memory again with the Porsche System Tester II No. 9588. Additional causes of faults that could damage the 'Tiptronic control module' should be detected and remedied.
DANGER:
Danger of burns from hot ATF fluid.
Skin or clothing may burn following contact with hot ATF fluid.
- Always allow ATF fluid to cool before draining.
- Wear suitable protective clothing.
- Use a suitable collecting container.
