Temperature Sensor, Transmission - Open Circuit/Short Circuit to B+, Short Circuit to Ground

P0710

Temperature sensor, transmission - Open circuit/short circuit to B+, short circuit to ground

Function
The temperature sensor controls the transmission's modulation pressure in accordance with the ATF temperature. This ensures soft shifting over the entire temperature range.

If the ATF temperature is too high, the control unit selects a map with the lowest possible power loss and closes the torque converter lockup clutch.

In addition, downshifting also occurs at high engine speeds. This helps to reduce the torque converter slip and permits the ATF to cool down. The sensor is defective if its voltage exceeds or falls below the stipulated voltage range. Shifting operations then take place with an 80 °C default value.

Diagnosis conditions
If an ATF temperature outside the limit range below - 50 °C or above + 170 °C is recognised, a fault is stored if the ignition is on.

P0710:

Wiring diagram







Diagnosis procedure

NOTE: The ATF temperature can be checked with the Porsche System Tester 2 (actual values/temperature).







1 Check temperature sensor with wiring.

1. Pull off Tiptronic control module connector.
2. Connect ohmmeter to Tiptronic control module connector, pin 21 and pin 22.

Indication: At 20 °C = approx. 1.00 kOhms
At 40 °C = approx. 1.15 kOhms
At 60 °C = approx. 1.30 kOhms

2 Check wires from Tiptronic control module to transmission connector for continuity.

1. Additionally pull off connector on transmission.
2. Connect ohmmeter to Tiptronic control module connector, pin 21, and transmission connector, pin 14 (or pin 22 and pin 13).

Indication: 0...5 Ohms

If Infinity Ohm is indicated, check wiring harness for crushing and chafing damage.

2 Check wires from Tiptronic control module to transmission connector for short circuit to ground.

1. Connect ohmmeter to Tiptronic control module connector, pin 21, and ground (or pin 22 and ground).

Indication: Infinity Ohm

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

2 Check wires from Tiptronic control module to transmission connector for short circuit to plus.

1. Switch on ignition.
2. Connect voltmeter to Tiptronic control module connector, pin 21, and ground (or pin 22 and ground).

Indication: 0 Volts

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