Diagnosing system faults (Freelander 2)

The Terrain Response control unit stores information about detected Terrain Response faults and CAN bus errors. This information can be read using the IDS. The Terrain Response subsystems and the instrument cluster also store CAN bus error information from the Terrain Response control unit.

The control unit also stores mileage and elapsed time data for individual programs, which can then be read using the IDS. It simplifies diagnostics of the Terrain Response system and allows the detection of incorrect use of the Terrain Response system by the driver, which can lead to premature failure of components.

This information can also be used to verify customer complaints, such as increased fuel consumption caused by prolonged use of a particular program.

Troubleshooting the Terrain Response System

The Terrain Response system depends on the correct operation of 4 subsystems. If any one of these subsystems fails, the Terrain Response system will not operate, although this is NOT a fault with the Terrain Response system itself.

The Terrain Response control module and rotary control should only be inspected if there are no apparent faults in any of the subsystems. If the fault in the subsystem is subsequently corrected, the Terrain Response system will return to normal operation after an ignition on/off cycle.

Terrain Response Subsystem Malfunctions

If a fault occurs in a subsystem, the driver will be notified by a warning light or a message for that subsystem in the instrument cluster message center. There will be no warning about a fault in the Terrain Response system.


If there is a subsystem fault and the driver attempts to select a different Terrain Response program using the rotary control or the next time the ignition is switched on, the message "SYSTEM FAULT SPECIAL PROGRAMS NOT AVAILABLE" will be displayed in the message centre. This message indicates that the Terrain Response system has a fault, but this is only due to a subsystem fault. This message will be displayed for 5 seconds when the ignition is switched on, but will be repeated if the driver attempts to use the Terrain Response rotary control or after each subsequent ignition switch.

Note: The message "SYSTEM FAULT SPECIAL PROGRAMS NOT AVAILABLE" appears on the display. SPECIAL PROGRAMS ARE NOT AVAILABLE) can also be caused by a malfunction of the rotary controller of the Terrain Response system or the control unit. Refer to the following information for a detailed description of the rotary controller or control unit malfunctions.

The Terrain Response control unit cannot cause any of the 4 subsystems to malfunction (turn on the indicator or display a warning). The illumination of the subsystem indicator and/or the appearance of the corresponding message are NEVER associated with the operation of the Terrain Response control unit or with a malfunction of the Terrain Response system.

The subsystem control units can detect a malfunction based on the signal transmitted by the Terrain Response control unit via the CAN bus. If a Terrain Response system malfunction is detected, the subsystem control units will operate in the special programs shutdown mode ("Special Programs off"). The subsystem control units will record a fault code based on the signal transmitted by the Terrain Response control unit via the CAN bus. Information about these faults can be read using IDS and is useful for diagnosing the Terrain Response control unit or the CAN bus.



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Rotary control or Terrain Response control unit faulty.

If the Terrain Response rotary control fails, all yellow LEDs illuminating the control symbols will be switched off and rotation of the control will be ignored. If a subsystem fails, the message "SYSTEM FAULT SPECIAL PROGRAMS NOT AVAILABLE" will appear in the instrument cluster message centre if the fault is present and the driver attempts to select a special program (if the control unit is capable of doing so) or the next time the ignition is switched on.

The rotary control and the Terrain Response control unit are a single unit. If one of these components fails, the entire unit must be replaced. BEFORE REPLACING THE TERRAIN RESPONSE CONTROL UNIT, MAKE SURE THAT IT IS THE FAILURE AND NOT THE CONTROL UNIT OF ONE OF THE SUBSYSTEMS.

If there is a CAN bus fault that prevents the Terrain Response system from operating, all yellow LEDs illuminating the rotary control symbols will light and the rotary control rotation will be ignored.

If the instrument cluster does not receive a CAN bus message from the Terrain Response control unit, the following message will appear on the information centre display in the event of a fault: "SYSTEM FAULT SPECIAL PROGRAMS NOT AVAILABLE" and this message will appear at each ignition cycle.

User error

The system's response to the following incorrect user actions may be mistaken for a system malfunction:

• The engine is not running - the program is changed and messages are displayed on the screen only when the engine is running
• An attempt is made to change the program with the DSC or ABS system active (this includes ABS cycles when using the hill descent control system on slippery or loose surfaces).
• An attempt is made to change the program when the active clutch overheats.