I have a 2001 330 ci auto convertible and have read i have a temp fault code, P1620. I have read in places this is due to the thermostat, how does the computer know the thermostat is having issues. My dash gauge gets up to temp really quick and sits in the middle of the clock (operating range) never moves from there until the engine cools.
Do i replace the temp sensor at the bottom of the radiator or do i have to replace the thermostat, if the thermostat how easy is this a job on a drive?
Thank you in advance.