With P1956

P17D8

Diagnosis information - PDK

Plausibility check of shift rods

Diagnostic conditions
The control unit initially tests internal function sequences when the ignition is switched on (terminal 15). If they are OK, all diagnosable outputs are then tested and any faults are stored.

- Ignition on
- The following fault is not detected: P1731
- The following fault is not detected: P1732
- The following fault is not detected: P1733
- The following fault is not detected: P1734
- The following fault is not detected: P1706
- The following fault is not detected: P1707

Possible fault causes
- Hydraulic control unit faulty

Fault setting conditions
- Current gear 2, 4, 6 or R is disengaged instead of new gear engaged
- Incorrect shift rod moves by more than 1.5 mm

Fault effects
- Shift operation abort
- Old gear is engaged again
- Engaged gear is held until vehicle stops
- Gearshifts possible only between the gears R, 2, 4 and 6
- Moving off possible only in 2nd gear
- No pre-engagement of next target gear
- Transmission limp-home indication in instrument cluster control unit