Andy,

Do you get bad temp readings all the time or only when something else happens, like while transmitting on the radio?  (The Davtron temp display in my Commander 112 jumps around when I transmit or if I'm within a mile or two of a very strong RF transmitter; i.e. radio/TV tower.  I'm guessing it's not shielded properly but hey, it was installed by a certified avionics shop.) Is it ok on the ground and bad in the air?  Are the bad temp readings displayed on the VM1000C or does it pass information to an EFIS and it shows up wrong on the EFIS?  The reason I ask this last question is because I saw an installation where the ADC passed temp data to an EFIS but the EFIS was sometimes displaying the ADC data and sometimes displaying another sensor, causing the reading to jump around.  The problem in this case was fixed with an EFIS firmware update.

Tom Gourley