Fronts not plugged.

To check the module , would that be in ecu info on GAP, I have checked fuse for P aid several times it has been good at all times Ecu info on GAP checked and parking module doesn't exist ?
I did a number of thing like vehicle reset , went back to rears only in ccf and rears working with dash light and sounder , bazarre! Perhaps I dont know enough . Put the bumper back on and pulled out sensor holders for testing meantime.

Ah , been caught out sensor holders wont go back in together with sensors.........bumper off again , damm it!

Update , bumper back of new sensors fitted all showing 9-10 on ohms , not really so much of a difference from the ones unwilling to function. So all working with Both selected on GAP . Happy Days!