Coding Control Unit For Four-Wheel Drive (PTM)

This procedure must be used if the values or coding cannot be read out from the control unit.

NOTE: Voltage drop

→ 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 additions may appear in PIWIS Tester II 9818 .

Information

The procedure described must be applied when a control unit has to be replaced and the tester function Control unit replacement cannot be used.

PIWIS Tester II 9818 must be connected to the vehicle and ignition switched on.
Select the vehicle type and start the PIDT.
Switch to the Additional menu and perform vehicle handover by pressing [F8].
Select Erase all fault memories in the menu and press [F12].
Carry out automatic search of control units.
Press [F12] to switch from the vehicle type to the list of control units.
Select PTM and Maintenance/repairs with the cursor keys and press [F12].
Select Control unit replacement with the cursor keys and press [F12].
Information

If the test step Control unit replacement - Read data cannot be run, the test step Control unit replacement - Write data must still be performed after installing the new control unit! This writes the basic identification data into the control unit.
Go to the Write data menu and press [F12] to continue.
The System Tester displays the message Data has been written . Press [F12] to continue.
Change to the Codings menu and compare the coding with the vehicle equipment. Re-code if necessary.
1. 11.1. Select the vehicle type and press [F8] to start coding.
Exit the menu, carry out a test drive, and read out the fault memory.