Mmmmm ...
Interesting .... (puts on Engineers cap) ...
Have to admit I don't know anything about the 109S electronics ... but this looks like an electrical glitch.
First step is to relax ... get wet line gauge out of stores and actually check what the REAL pressure indication is.
If gauge reads the same as indicated on No1 Eng Prx per screen you then it would appear the caution light sensor is the problem. If gauge readings are "normal" then the hunt begins looking for the earth/grounding fault or the dodgy transmitter. Perhaps substituting the caution transmitter with the appropriate resistor value will make the display behave and then point you in the right direction ...
Q. On this machine does the Eng prx signal and the caution Lt signal originate from the same sensor?
Should be (Ha Ha) an easy (ish) fix! ... or perhaps a job for the "queer trades" guy??
Good Luck
