Calibration Selection

On vehicles from 1999 model year, the auto gear box control unit contains 2 calibrations. One for the 4.0L engine and one for the 4.6L engine. When a replacement auto gear box control unit is fitted, the correct auto gear box control unit calibration must be selected or the auto gear box control unit will store a automatic transmission fault and GEARBOX FAULT will be displayed in the message center. The vehicle can still be driven and will not switch to limp home mode.

A removed automatic transmission control unit remembers calibration settings and if reinstalled to the same vehicle will not require calibration. A new automatic transmission control unit will require calibration using Land Rover Testbook/T4 scan tool.

If automatic transmission control unit is installed from another vehicle, the message center will not display the GEARBOX FAULT message. The correct calibration level must be selected or premature automatic transmission failure will occur.