The ambient temperature readout on the touch-screen of our '07 XK (77k miles) has always read high by 5 degrees Fahrenheit. This has been verified by comparing the readout to our '11 XJ parked next to it in the garage, local thermometers, etc. The readout of my prior Jags have been spot on. A few questions:

1. Has anyone else noted this with their XKs?
2. While doubtful, is there any adjustment to correct this or to provide a simple way of including an offset (other than in our heads) to do so?
3. Does the reading reflect what the engine ECU is seeing, i.e., is the same output used for both?

Thanks.

 

The external temp readout on your XK is similar to what mine is. Be aware that the sensor that provides the data for the readout that appears on your screen is placed in front of the radiator and is aimed down towards the pavement. Basically that is why the readout is several degrees higher than that reported by thermometers that read ambient air temperature.

 

Ralphwg, Thanks for the input. I went to the garage this morning after reading your post and measured the temperature around, on, and under the fronts of XJ and XK with my IR thermometer. Average was 63.5+/- 0.5F. Reading on the XJ touch screen and IP: 63F. Good. Reading on the XK touch screen: 60F. Not far off, but not the 5F high that I expected. Given this, I took the car for a drive just now. Ambient local temperature per Weather Underground was 55F. The reading while driving the car: 55F! Good, but there is no doubt that the readings are high when the temps are 70F and above. Looks like I need to gather more data.