Preliminary Work
- If a new control unit has to be installed, the values/coding must be read out using > 9818 - PIWIS Tester II prior to removing the "old" control unit.
- Remove right front seat.
- Remove inner door entry guard on the right.
- Remove control unit for rear-differential lock.
> 397519 Removing and installing control unit for rear-differential lock - "REMOVING "