Manufacturer Codes: 90

Fault, DTC 90 Test Point 14

Gear sel. monitor, output drive
Signal implausible

Possible causes, elimination, notes

Fault effect:
Reduced driving program.

The ratio of transmission input speed/transmission output speed is monitored.
1. Check sensor for the transmission speed on Tiptronic control module connector pins 14 and 42 with an ohmmeter.

Nominal value:0.80... 1.2 kOhms.

2. Check wiring from the control module connector pin 42 (or 14) to the 16-pole transmission connector pin 10 (or 1) for open circuit, short circuit to ground and short to B+.
3. Check shield on control module connector pin 15.
4. Test sensor on transmission socket pins 10 and 1 with an ohmmeter.

Nominal value: 0.80... 1.2 kOhms.

NOTE: The ATF pan must be removed before the sensor can be replaced.

5. If items 1... 4 are OK and no other faults are stored, there is a mechanical/hydraulic fault in the transmission (e.g. ATF level not OK, slipping clutches or brakes).