Someone above said to check ripple on DC. Very good suggestion. Does the call you registered to run the car cancel when the car levels back to the floor? If it does your power is probably bad somewhere. Does it do the same both directions or only down? Make sure the 24V and 5V do not drop when car starts, This would be an indication of a bad filter and ripple. Do not let the 5v drop below 4.8. If you have to adjust 5v to 5.2v. If the call does go out when it levels back you probably rebooted power supply for some reason. I believe there are some relays and it is possible for an armature rivets loose and contacts not making. Examine all the relays carefully. Good Luck.
