In my 91 LS400, I have the Suspension Height Control System with the options for Norm/High and Sport/Norm next to the shifter.

When I change these switches, I don't notice any difference in anything and also the lights in the dash don't light up on any setting. Almost as if there were no Height Control System at all.

Any ideas to pin-pointing the problem. I have checked all fuses and tried the switch in the First Aid box in the trunk.

Thanks.

 

I have the system in my '94.

You should see lights change when you move the switch. Try key off, then key on, all the display lights should come on momentarily.

On the sport / norm, w/ engine off but key on, all you will here is a quick motor changing the damping rod on the top of ea strut, you can barely hear it.

On the norm / high, the compressor should come on, for about 40 sec to raise the car. Going back down you will hear air release from the right front area, where one of the master control valves are.

To be sure you have A/S, look at each strut, it is noted on the top and looking under the car you will see air struts not springs. And there will be a small link from ea control arm to the body (height sensors) And yes the master switch in the LH rear trunk TOOL side, not FIRST aid side (at least on my car)

You should check all the fuses too.

Good luck.