2005 XJ8: At cold startup, when I select R the rear parking warning gives a false alarm and sounds continuously until D is selected. After driving the car for a bit, the warning seems to work normally (or at least it doesn't false alarm when selecting R). Any thoughts, could a failed sensor cause this?

 

Cols weather and ice can cause this, but I see you're in Florida !

 

I don't remember if the Rear Park Aid stores DTCs in the module but I know it is on the SCP network.

Might be worth having the module interrogated?

 

You have a faulty rear sensor

My Car soft scanner picked up a faulty sensor DTC

 

Mine does the same thing and its a dodgy sensor, drivers side centre.

 

Thanks for the replies, I will check the sensors.