help mga bros....my back up unit suddenly makes continuous beep/sound everytime i shift to reverse, this started last night when my battery was discharge so have to push backward coz the inclined road was at the back...i was able to start the van but the reverse beep/sound suddenly malfunctioned, what could have cause this? the module or the sensor all four or just 1 0r 2? thanks for those who can share his experience on this...