I've had the "F" a few times, mainly when i've been playing with opcom, oops LOL. But it's also happened on mine when I forget to reconnect the outside temp sensor when I take the bumper off and also when I had "CIM" symptoms. I think it might signifies a communication fault with one or more of the cars modules.
Now this is where it might help, the CIM is the Column Integration Module, one of about 22 ECU's on the car. The CIM has several things going through it like all the dash dials, steering angle sensors, so ABS/TC and the main thing that might concern you is the Imobilisor unit. When I had what I thought was CIM problems one of my symptoms was the car wouldn't start due to the imobililisor. Any how one of the Vec C's other quirks is the CIM takes some or all its power through the ABS Module, and as you've guessed the both the CIM and ABS Module both carry Field Remedy numbers so are both known to have faults with VX, but not really on your reg plate but you never know. Check the Fuses in the box on the passenger side if the Dash (the passenger door covers it) and what sorted mine was cleaning the ABS plug which is above the battery box, pull the tab and the plug lifts off, just spray it with contact cleaner ( I used WD40). Once I did this ive never had a problem in years.
