If a toyota land cruiser height control does not work, what should be done?

First, check to see if the vehicles fuses are functioning correctly. To do so, disconnect the height control wires and then, reconnect them to see if the mechanism works. If this doesnt work, Youll need to perform a diagnostic test on the cars ECU to see whats preventing the height control from working properly. At this point, You can try plugging in a code reader to see just exactly whats going on between Your ECU and the systems its transmitting to. You should also check all the wiring to make sure everything is in order and nothing is cut. If it is still being buggy, You should take the vehicle to a mechanic or an auto-electrician to get it looked at immediately.