My ambient air temperature sensor (AATS) was never as far off as some mentioned earlier in this thread but it always read wrong. It was typically 10-15C above what the actual temperature outside was. I thought it was due to it's position so I relocated it lower, & away from any heat soak. No change. I thought odd - saw the AM tech bulletin referenced earlier so decided I'll just replace it. Problem solved.

Why bother? I've never had the pleasure of analysing Aston Martin engine ECU logic but if it's anything like other manufacturers (I.e. BMW) the AATS can impact heavily on the operation of the engine in determining the fuel/air mixtures and the operation of the climate control. Some makes have multiple air temp sensors including using the MAF(s) (beyond just volume) and additional intake manifold air temp sensors to improve accuracy - but every sensor piece of input into the engine ECU can be considered to determine outcomes via algebraic calculations and logic decisions. .

Other related actions including the correct operation of climate control systems can be off when the vehicle thinks the outside air temp is something other than it actually is. I'v seen dozens of (BMW) owners who cannot get the AC on cause the ECU believes it is minus 40C outside and prevents the operation as a safety.

In my quest to replace the AATS I stumbled onto another OE cross reference - the sensor is actually made by GE for several makes including Land Rover, Rover, Toyota, Lexus and Mitsubishi. The core GE number is 0775005191 - makes finding it and shipping it much simpler. I ordered mine on Amazon for a Prius and had it in 2 days - free shipping.

 

Guys:
The temp sensor is cheap, very easy to replace and cures a multitude of issues related to both interior and engine temp issues. Remove the slam panel and you can reach down to get your hand on the sensor. I got my new sensor from Redpants and installed it in about 20 minutes.

 

If the temperature is off more than 10% it's a good idea to change it, as mentioned above it has an effect on multiple items on the car from how the top operates on a Roadster and how the clutch engages and releases on a Sport Shift vehicle as well.

Good reference on the part # and source!