Fail to connect to the engine processor module thru OBD II connector on a 98 XK8 convertible

Hi there,
I purchased another XK8 convertible.It is a '99 (?) year model however date of first registration was 12/98. Part of my pre-buy inspection was trying to read out out any codes which might have been stored. But for some reason I could not access the engine processor module. I used an “I-Carsoft” LR V2.0 OBD-reader which works fine on my '01 XK8. It’ll let me choose on model & year. Tried both '98 &'99 model year but it always tells me “no communication with engine processor module”. Checked already fuses like OBD II connector, etc. Any input would be appreciated…