Transfer Box Power Flow: Diagnostics

The transfer box control module can store fault codes, which can be retrieved using T4 or a diagnostic tool using KW2000* protocol.

The information is communicated via a diagnostic socket.

The diagnostic socket allows the exchange of information between the various control modules on the bus systems and T4 or another suitable diagnostic tool. The information is communicated to the socket via the CAN bus. This allows the retrieval of diagnostic information and programming of certain functions using T4 or another suitable diagnostic tool.

The transfer box control module uses Diagnostic Trouble Codes (DTC), which relate to transfer box electrical faults.

CLUTCH AND RANGE CHANGE MECHANISM CALIBRATION

In order for the range change mechanism to function correctly, the transfer box control module must be calibrated to the mechanical dimensions of the transfer box that it is connected to.

This procedure will need to be followed if one of the following occurs:

• The switch is changed
• The transfer box control module is changed
• The transfer box or range position sensor is changed
• Vehicle or transfer box control module fault has caused the transfer box to revert to an undefined range.

Calibration can be carried out using T4.

MANUAL TRANSMISSION GEAR LEARNING PROCEDURE

The transfer box control module contains an adaption that enables it to recognize which gear the driver has selected. The adaption has to be reset, by performing the gear learning procedure, if one of the following occurs:

• The transfer box control module is reprogrammed or replaced
• The manual transmission is replaced
• The gear position sensor is replaced

During the gear learning procedure the vehicle must be driven smoothly in all gears, with the clutch fully released in each gear, in a single drive cycle. The procedure can be performed with the transfer box in either high or low range.

Gear Learning Procedure

1. If the gear learning procedure is to be performed because the manual transmission or the gear position sensor has been replaced, use T4 to set the gear adaption status to 0 in the transfer box control module.
2. Start the vehicle.
3. Drive in reverse gear and fully remove your foot from the clutch, drive in reverse with your foot off the clutch for 3 seconds and ensure that R is displayed in the instrument cluster.
4. Drive in 1st gear and, when gear position 1 is displayed in the instrument cluster, change to the next gear. Continue driving, and changing up to the next gear once the current gear is displayed in the instrument cluster, until gear 6 is displayed in the instrument cluster, then stop the vehicle.

5. Stop the engine, remove the ignition key and wait for a minimum of 60 seconds (for the transfer box control module to power down).

6. Insert the ignition key and turn the ignition switch to position II (ignition).
7. Select each gear in turn. If the appropriate gear position is displayed in the instrument cluster as soon as each gear is selected, the gear learning procedure has been successful. If the gear position is not displayed in the instrument cluster, the gear learning procedure has failed and must be repeated.
   • NOTE: T4 can also be used to check if the gear learning procedure has been successful.