Yes its strange, INPA clearly identified faults on 1 front(Left centre) and 3 rear, I swapped the left rear(the one not showing an error) with the faulty front one, diagnostics then showed all four rear in error, nothing on the front at all!! I have tried all the recommended listening to them and so forth but have never been able to identify if any are working or not, the fault is when put in reverse the beeper gives one long beep and the green light flashes. I have changed the module, the fault remains the same!!