Valve Body: Service and Repair
Removing and installing electrohydraulic control unit
Information
Overview of tightening sequence for hydraulic control unit
Always observe tightening sequence. The screw heads of the Torx screws used to secure the electrohydraulic control unit to the Porsche Doppelkupplung housing are slightly bigger (Torx T40) than the screws for the flange blocks of the electrohydraulic control unit.
Preliminary work
1. Move selector lever to position P.
2. Raise the vehicle at the prescribed jacking points.
3. Remove rear underbody panelling.
4. Drain ATF.
5. Remove ATF oil pan.
Removing electrohydraulic control unit
Overview of tightening sequence for hydraulic control unit
1. Remove electrohydraulic control unit.
1.1. Unscrew screws 16 and 18.
1.2. Screw two M6 x 95 mm screws - Part No. 900.385.126.01 approx. 10 mm into screw holes 16 and 18.
1.3. Unscrew the remaining screws in reverse tightening sequence and carefully set the electrohydraulic control unit down on the long screws.
1.4. Remove the temperature sensor at the electrohydraulic control unit.
Removing and installing temperature sensor on switch unit
Unscrew screw -2- (Torx T27) on electrohydraulic control unit -1- and pull out the temperature sensor -3-.
1.5. Pull off cable plugs on solenoid valves.
Releasing connectors on solenoid valves
Carefully release cable plugs -1, 2- on the solenoid valves -3, 4- and pull them off the solenoid valves -arrow-. Do not bend locking lugs too much when doing this.
Information:
If the connector housings are damaged during removal, always replace them.
1.6. Unscrew the long screws and remove the electrohydraulic control unit.
Installing electrohydraulic control unit
Information:
Before installing the electrohydraulic control unit, check the sealing surfaces of the control unit and the sealing surfaces of the transmission for damage and soiling. Damaged or soiled parts must not be used. Ensure absolute cleanliness when installing the electrohydraulic control unit.
Information:
If a new hydraulic control unit is installed, the transmission must be calibrated using the PIWIS Tester 9718.
Overview of tightening sequence for hydraulic control unit
1. Install electrohydraulic control unit.
1.1. Position gear support approx. 10 cm under the transmission and then place the electrohydraulic control unit on the transmission jack.
1.2. Fit the temperature sensor at the electrohydraulic control unit.
Removing and installing temperature sensor on switch unit
Fit the temperature sensor -3- and check that it is installed at the correct position above the oil bore. Screw in and tighten screw -2- on the electrohydraulic control unit -1-.
- Tightening torque: 6 Nm (4.5 ftlb.)
1.3. Fix the electrohydraulic control unit in place under the transmission using two screws (M6 x 95 mm). To do this, fit the two screws through the screw holes for screws 16 and 18 on the electrohydraulic control unit and screw in by approx. 10 mm.
1.4. Connect cable plugs at the solenoid valves.
Connect cable plugs -arrows- to the solenoid valves -1, 2- and check that the cable plugs -arrows- are engaged correctly.
Disconnecting and connecting solenoid valves
1.5. Secure electrohydraulic control unit to the transmission.
Information:
The wire harness for the solenoid valves -3- and the cable for the temperature sensor -4- must be routed in the recess between the transmission housing -2- and electrohydraulic control unit -1- because otherwise the cables can become squashed, resulting in damage and malfunctions.
Wire harness routing
^ Check that the wire harness is positioned correctly after installing the electrohydraulic control unit.
^ Make sure that the electrohydraulic control unit is flat on the Porsche Doppelkupplung housing.
^ The electrohydraulic control unit must be positioned exactly with respect to the port plate.
^ Fit and tighten screws -1 to 15- in the specified sequence.
^ Unscrew the long screws.
^ Fit and tighten screws -16 to 20- in the specified sequence.
^ Check the position of the electrohydraulic control unit again.
^ Tighten screws -1 to 20-.
Step: 1
- Tightening torque: 1.5 Nm (1 ftlb.)+1.5 Nm (+1 ftlb.)
Step: 2
- Tightening torque: 8 Nm (6 ftlb.)
Subsequent work
1. Install ATF oil pan.
2. Fill in ATF.
3. Check and if necessary, top up ATF.
4. Install underbody panelling.