Replacing Control Unit For HV Battery

→ 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 PIWIS Tester to the vehicle and start it. Switch on ignition.
2. Select the vehicle type and start the diagnostic application.
3. Select the High-voltage battery  control unit in the overview  .
4. Maintenance/repairs  must then be selected.
5. Control unit replacement  must now be selected. Then press [F12].
6. Read data  must now be selected. Then press [F12].
7. Press [F8] to start reading out data.
8. Check the chassis number and press [F12].
9. Switch off ignition and replace the HV battery control unit. → 279419 REMOVING AND INSTALLING CONTROL UNIT FOR HV BATTERY .
10. Switch on ignition. Select the Write data  menu (procedure described above), press [F12] and then press [F8] to start installing the data that was read out.
11. The System Tester displays the message Data has been written  . Press [F12] to continue.
12. Select the Automatic coding  function and follow the instructions on the Tester.
13. Read out the fault memory and erase it if necessary.
14. Function test: Perform a test drive.
15. Read out the fault memory.