Hey fringe30
That is the ARC system warning light. It is telling you that something is not right in the rear air suspension.
First off check the sensor attached to the rear axle and body is still attached at all the little ball joints. Then make sure both the air lines going into the shocks are seated properly in the conector(push it in and pull it outwards should hold fast).
You can reset it by turning off the switch in the hatch in the cargo area,raising the rear off the ground to let the wheels hang for 10 mins or so then lower to the ground. Make sure all the doors and windows are closed then turn the switch back on and close the rear hatch. The compressor should then cycle to raise the susp to it's ideal height.
If after doing a reset you still get the light coming on after a bit of a drive then you could have a leak in one of the shocks.
It could be just sag in the springs is working the compressor to hard. I was having similar problems with my ARC, coming on 15 mins of cruising. i replaced the load sensor, check my lines and was gonna replace my shocks but for some reason i decided to put some lifted shackles on the rear with an extension bracket for the load sensor and this solved my problem!!!
HTH
PS come say hi to the guys in the uk section
