It had been popping up for a couple of weeks on ultra gauge as pending and then the service engine light came on/ultra gauge pending changed to trouble code. Is there any reasonable way to remove this thing or does the fan and the wheel coming off the cam shaft have to be removed? Any thing else I should check first? Should I drive with it till I get it fixed or leave it parked?

2004 Land Rover Discovery with 75,000 miles. This first started happening will going down a pretty ruff road.

 

You mean the crank pulley (harmonic balancer). May be able to get a wrench behind it. But if you can get to the harness, check on the condition, code is for wiring problem.