P0710
P0710
Temperature sensor, transmission
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 a 60°C default value.
Diagnosis conditions
A fault is detected and stored when the ignition is switched on.
Wiring diagram
Diagnosis procedure
NOTE: The ATF temperature can be checked with system tester 9288 (actual values/temperature).
Check temperature sensor with wiring.
1. Pull off transmission control unit connector.
2. Connect ohmmeter to transmission control unit connector, pin 21 and pin 22.
Indication:
At 2O°C = approx. 1.00 kohms
At 40°C = approx. 1.15 kohms
At 60°C = approx. 1.30 kohms
Check wires from transmission control unit to transmission connector for continuity.
1. Additionally pull off connector on transmission.
2. Connect ohmmeter to transmission control unit connector, pin 21, and transmission connector, pin J (or pin 22 and pin D).
- Indication: 0...5 ohms
- If infinite resistance ohm is indicated, check wiring harness for crushing and chafing damage.
Check wires from transmission control unit to transmission connector for short circuit to ground
1. Connect ohmmeter to transmission control unit connector, pin 21, and ground (or pin 22 and ground).
- Indication: infinite resistance
- If 0...5 ohms is indicated, check wiring harness for crushing and chafing damage.
Check wires from transmission control unit to transmission connector for short circuit to plus.
1. Switch on ignition.
2. Connect voltmeter to transmission control unit 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.