Pontiac Repair: Temp gauge 07 G6, gauge info, scan tool

Question
Hi. I have an 07 G6,3.5 v6,60k.My temp gauge just started malfunctioning. The gauge doesn't register any temp at all(above 100 starting point) then sometimes is intermittent,gauge cycles up & down on start up. The cooling fans work sometimes when the gauge does not,and sometimes they don't work when the gauge does not. The A/C also occasionally doesn't cool when gauge does not.I'm sure this probably means overhaeting as well, but I can't tell w/out a gauge. I was thinking about the coolant sensor befpre the fan relays but was not quite sure if this was the correct sequence.I'm not sure if the problem lies w/ the sensor or one of the fan relays or exactly where they are located. as I'm having trouble finding a current repair manual for this year.Please help.
Thanks

Answer
Hi dave.
if this has less then 36,000 miles it still under warranty.

it can be a temp sensor but you would have a service engine soon lamp and possably the fans would run all the time. It's a fail safe mode to make sure the engine doesn't overheat. the same sensor that runs the gauge is the same one for the engine control module the engine module sends out the gauge info to the cluster and the gauge will work from the info it receives from the engine module. you need a engine scan tool to see what the temp reading is into the module. the reason you can't find a repair manual is due to the fact the car is too new and usually still under warranty. untill you see what's going on here it's hard to say for sure what the issue is either the sensor is bad and sending bad info to the emgine module or the engine module is sending incorrect data to the cluster or the cluster is bad. with a scan tool you can also see what the cluster is receiving as info and then if the guage is reading what the info ir gets or the guage is just bad.. good luck :)