Paul, the range on message centre IPK is calculated from the mean value of the two fuel tank senders which is an analogue signal converted to a digital one within the IPK, and the injector pulsewidth signals derived from the ECM which is transmitted to the IPK on the CANBUS.
It is a strange one, and I would suggest a hard reset on the IPK, (battery off for five minutes, then reconnect)
Have fun
Brian
