Reading And Writing Values

→ Prior to disconnecting the control unit, switch off ignition and remove ignition key.

→ Ensure that the power supply is not interrupted during programming.

→ Connect a battery charger with a current rating of at least → Nominal value: 40 A  to the vehicle battery.

Information 

The PIWIS Tester II 9818  instructions take precedence since the description may be different with later Tester releases.

The procedure described here has been structured in general terms. Different text or additional information may appear in PIWIS Tester II 9818  .

1. Connect the Porsche System Tester to the vehicle and start the System Tester.
2. Switch on ignition and press [F12] to continue.
3. Select the required vehicle type.
4. Select the required control unit, e.g. Trailer hitch  in the overview  .
5. Maintenance/repairs  must then be selected.
6. Control unit replacement  must now be selected. Then press [F12] to continue.
7. Read data  must be selected. Then press [F12] to continue.
8. Press [F8] to start reading out data.
9. Check the chassis number and press [F12] to continue.
10. Switch off ignition and replace control unit. → 669619 REMOVING AND INSTALLING TRAILER HITCH CONTROL UNIT .
11. Switch on ignition, select the Write data  menu (procedure described above), then press [F12] to continue.
12. Press [F8] to start installing the data that was read out.
13. The System Tester displays the message Data has been written  . Press [F12] to continue.
14. Fault memory  must be selected and erased if necessary.