Hi limuman
I experienced exactly the same symptoms with the 'overheating' indication interrupting a couple of long trips.
In discussion with the Mitsubishi Dealership in Cape Town, as well as this forum, it always came back to the same answer....
THE CIRCUIT BOARD THAT CONTROLS THE FUEL AND TEMPERATURE GAUGE NEEDS REPLACING!!!
I finally capitulated, spent R2000 and had the
CIRCUIT BOARD replaced!!
As mentioned in previous postings, the
MILEAGE HAS BEEN RESET.... and after having an 11 year old SWB with 266000kms on the clock, I now have a 2002 3.2 DID GLS SWB with
ONLY 350KMS ON THE CLOCK..

... Good condition, too! Think I will get a good price for it???
The good news is that the Temperature Gauge indicates a nice, cool, steady reading.
Now all I need is to find one of those
AUTO ELECTRICIANS WHO WILL MANIPULATE MY MILEAGE......LEGALLY, OF COURSE!!
Curly