Manufacturer Codes: 37

Fault, DTC 37 Test Point 25

Transmission temperature sensor
Open circuit/short to B+

Possible causes, elimination, notes

Fault effect:
Reduced driving program.
Substitute value of 80 degrees C for ATF temperature.
No activation of the coolant switchover valve (transmission always cooled).

NOTE:
- The ATF temperature can be checked with the Porsche System Tester 2 (Actual values/Transmission temp.).
- A fault is stored if an ATF temperature outside the limit range below - 50 degrees C or above + 180 degrees C is detected.

1. Check ATF level.
2. Check sensor for ATF temperature with wiring. To do this, connect an ohmmeter to control module connector pins 21 and 22.

Nominal value:
At 20 degrees C = approx. 1.00 kOhms.
At 40 degrees C = approx. 1.15 kOhms.
At 60 degrees C = approx. 1.30 kOhms.

3. Check wiring from control module connector pin 21 (or 22) to the 16-pole transmission connector pin 14 (or 13) for continuity, short circuit to ground and short to B+.

4. Check sensor for ATF temperature with transmission wiring harness. To do this, connect an ohmmeter to transmission socket pins 13 and 14.

Nominal value:
At 20 degrees C = approx. 1.00 kOhms.
At 0 degrees C = approx. 1.15 kOhms.
At 60 degrees C = approx. 1.30 kOhms.

If the nominal value is not OK = the transmission wiring harness or ATF temperature sensor is defective.

NOTE: As the ATF temperature sensor is integrated in the transmission wiring harness, the transmission wiring harness must be replaced if the sensor is damaged.