Solar sensor is centre of dash between the two front windscreen vents and the interior ambient air temp sensor is behind the little grill close to your left knee. MY15
Tyre Pressure Monitoring System (TPMS)
Surround Camera System
InControl Apps soon to be replaced with CarPlay (WIP)
Meridian Premium Surround Sound
Digital Audio Broadcast
Timed Climate
Cruise ECO Data
Follow Me Home Reverse
Extra Features Menu
Picture In Motion
4x4i screen (WIP)
Digital Broadcast TV
Meridian Rear Media with WIFI
Factory Powered Tailgate
Blind Spot Monitoring (BSM)
Reverse Cross Traffic Alert (RCTA)
Electrochromatic Wing Mirrors (WIP)

Thanks Stuartc I talked to David at Team Valley LR and he said he'll try to find out some more. He thought if one of these sensor faulty, there should be faulty code logged but they didn't find any last week. I thought that a faulty sensor may not necessarily register a faulty code if it still functions even though the temperature reporting is much lower than the actual temperature.

If there's a fault it will be logged in SDD.
The interior ambient air sensor (by your left knee) can get dusty as it has a fan drawing air across it which whilst is not a fault and will not give a DTC it may affect readings and not result in the desired cooling temp. MY15
Tyre Pressure Monitoring System (TPMS)
Surround Camera System
InControl Apps soon to be replaced with CarPlay (WIP)
Meridian Premium Surround Sound
Digital Audio Broadcast
Timed Climate
Cruise ECO Data
Follow Me Home Reverse
Extra Features Menu
Picture In Motion
4x4i screen (WIP)
Digital Broadcast TV
Meridian Rear Media with WIFI
Factory Powered Tailgate
Blind Spot Monitoring (BSM)
Reverse Cross Traffic Alert (RCTA)
Electrochromatic Wing Mirrors (WIP)