Vehicle control system and method

1. A vehicle control system for controlling a vehicle transfer case operable in a high range and a low range and adapted to change range while the vehicle is in motion; the control system being configured to:

determine an operating range for the transfer case based on a selected vehicle operating mode, the selected vehicle operating mode defining at least one of: steering response; throttle response; engine mapping; brake mapping; output torque; anti-lock braking control; or wheel slip parameters; and

output a range change signal to implement a range change to engage the determined operating range.

2. A vehicle control system as claimed in claim 1 , wherein the control system is configured to receive an operating mode signal indicating the selected vehicle operating mode and to access a look-up table to identify the operating range defined for the selected vehicle operating mode.

3. A vehicle control system as claimed in claim 1 , wherein the control system is configured to identify the selected vehicle operating mode from a plurality of vehicle operating modes.

4. A vehicle control system as claimed in claim 3 , wherein said vehicle operating modes comprise a plurality of off-road operating modes and

wherein said off-road operating modes comprise one or more low range off-road modes requiring that the transfer case operates in said low range, and one or more high range off-road modes requiring that the transfer case operates in said high range.

5. A vehicle control system as claimed in claim 4 , wherein the control system is configured to output said range change signal to implement a change from said high range to said low range when the vehicle operating mode changes from one of said one or more high range off-road modes to one of said one or more low range off-road modes.

6. A vehicle control system as claimed in claim 3 , wherein said vehicle operating modes comprise at least one on-road operating mode requiring that the transfer case operates in said high range and

wherein the control system is configured to output said range change signal to implement a change from said low range to said high range when the vehicle operating mode changes from a low range off-road operating mode to said at least one on-road operating mode.

7. A vehicle control system as claimed in claim 3 , wherein said vehicle operating modes comprise a towing mode and

when said towing mode is selected, the control system is configured to output said range change signal to implement a range change based on vehicle speed.

8. A vehicle control system as claimed in claim 7 , wherein the control system is configured to output said range change signal to implement a range change from the low range to the high range when the vehicle speed increases above a first towing speed threshold; and/or the control system is configured to output said range change signal to implement a range change from the high range to the low range when the vehicle speed decreases below a second towing speed threshold, wherein the first towing speed threshold is the same as or different from the second towing speed threshold.

9. A vehicle control system as claimed in claim 3 , wherein said vehicle operating modes comprise a hill climb assist mode.

10. A vehicle control system as claimed in claim 9 , wherein, when said hill climb assist mode is selected, the control system is configured to output said range change signal to implement a range change based on vehicle speed and/or

to output said range change signal to implement a range change from the high range to the low range when the vehicle speed decreases to zero and/or

to output said range change signal to implement a range change from the low range to the high range when the vehicle speed increases above a hill climb threshold and/or

to output said range change signal automatically upon identification of a change in vehicle operating mode and/or

to output a user prompt requesting confirmation to implement said range change upon identification of the change in vehicle operating mode.

11. A vehicle comprising a vehicle control system as claimed in claim 1 .

12. A method of controlling a vehicle transfer case operable in a high range and a low range and adapted to change range while the vehicle is in motion; the method comprising:

determining an operating range for the transfer case based on a selected vehicle operating mode, the selected vehicle operating mode defining at least one of: steering response; throttle response; engine mapping; brake mapping; output torque; anti-lock braking control; or wheel slip parameters; and

outputting a range change signal to implement a range change to engage the determined operating range.

13. A method as claimed in claim 12 comprising receiving an operating mode signal indicating the selected vehicle operating mode and

comprising accessing a look-up table to identify the operating range defined for the selected vehicle operating mode.

14. A method as claimed in claim 12 comprising identifying the selected vehicle operating mode from a plurality of vehicle operating modes.

15. A method as claimed in claim 14 , wherein said plurality of vehicle operating modes comprise a plurality of off-road operating modes.

16. A method as claimed in claim 15 , wherein said off-road operating modes comprise one or more low range off-road modes requiring that the transfer case operates in said low range; and one or more high range off-road modes requiring that the transfer case operates in said high range.

17. A method as claimed in claim 14 , wherein said vehicle operating modes comprise at least one on-road operating mode requiring that the transfer case operates in said high range and

wherein the method further comprises outputting said range change signal to implement a change from said low range to said high range when the vehicle operating mode changes from a low range off-road operating mode to said at least one on-road operating mode.

18. A method as claimed in claim 14 , wherein said vehicle operating modes comprise a towing mode and

wherein the method further comprises outputting said range change signal to implement a range change based on vehicle speed in dependence on selection of said towing mode.

19. A method as claimed in claim 18 , comprising outputting said range change signal to implement a range change from the low range to the high range when the vehicle speed increases above a first towing speed threshold; and/or outputting said range change signal to implement a range change from the high range to the low range when the vehicle speed decreases below a second towing speed threshold, wherein the first towing speed threshold is the same as or different from the second towing speed threshold.

20. A method as claimed in claim 14 , wherein said vehicle operating modes comprise a hill climb assist mode and, further comprising,

outputting said range change signal to implement a range change based on vehicle speed when said hill climb assist mode is selected and/or

outputting said range change signal to implement a range change from the high range to the low range when the vehicle speed decreases to zero and/or

outputting said range change signal to implement a range change from the low range to the high range when the vehicle speed increases above a hill climb threshold and/or

outputting said range change signal automatically upon identification of a change in vehicle operating mode and/or

outputting a user prompt requesting confirmation to implement said range change upon selection of the vehicle operating mode.