saab 9000 "check engine" - 4 flashes

Hi - My 1996 2.3 lpt saab 9000 CD is now showing the "check engine" indicator... When I first turn the ignition switch... it flashes "check engine" 4 times repeatedly ...

looking at

my engine Trionic?In which case is "Coolant temperature sensor" a fair bet?

Car seems to run ok... but having run it at idle for about 20+minutes the Dash panel temp guage never rose beyond the "8oclock" position and the fan never came on once (though it is a cold day - 8c).

Where abouts is the "Coolant temperature sensor" on my car? Is it easy to test / replace?

In the meantime - is it ok to drive in this condition?

thanks for any help AJ