Freelander 2 (LR2) BCM Faults B10EA and B112C

Having cured my engine fault light alarm by replacing the throttle body module I have two new Diagnostic Trouble Codes:
B10EA Positive Temperature Coefficient Heater and
B112C Interior Motion Sensor.

With winter almost upon us I suppose I'll need to fix the heater, if only to keep the wife happy. As for the interior motion sensor, I'm not all that bothered.

The interior sensor is a common-ish issue, easily fixed with a replacement.

The PTC issue could have several causes, but start with the fuse and work from there.
Mine has a code which says the heater module isn't compatible, so I'm guessing it's been replaced by the wrong unit at some point, and I'm not 100% sure my PTC is working either, not that it's very effective.