I've got an XJR with the adaptive suspension where the previous owner has replaced the adaptive shocks with regular units. I tried unplugging the adaptive suspension computer and it gave me an ABS fault instead, which went away when I plugged it back in (Coincidence?). Has anyone found a trick to get rid of the "suspension fault" light under these circumstances?

 

You can first try by removing the Fuse No. 1 in the Engine Management Fuse Box.


If this does not eliminate the "suspension fault" (or cause more faults) put the fuse back in. The next thing you will need to do is simulate the presence of the solenoid valves that the adaptive shock absorbers have. To do this, get a number of 3W resistors from a radio shack in different values of around: 47, 33, 20, 15, 10 and 6.8 Ohm (4 of each). Find the now not used wires with connectors to the shock absorbers and connect a resistor to each of them, starting from 47 Ohm. If the message is still there, go to the next lower resistor value (Ohms) until you find which value eliminates the fault message. The 3W resistors look like this:


Then, you will have to replace the small 3W resistors with much bigger resistors of around 25W with the Ohms value as what you found when testing with small resistors that eliminated the fault message. You will need to mount these resistors somewhere to the car's body. The 25W resistors look like this:


The reason why you need to use the big resistors is the fact that the Adaptive Damping system will still operate and send current through the resistors "thinking" it is the solenoid valves and this current will cause some heating-up of the resistors. The Adaptive Damping will be "on" at speeds of less than 5 Mph, on harder cornering and/or harder braking. As these "on" sequences are not very long, there should not be too much heat generated by the resistors and, anyway, it will dissipate into the car body panel.

 

Stojanovic, thanks for that excellent write up. I will start with the fuse this evening and get parts on order if that does not work.

 

Well, I went to pull that fuse out and it was already blown so I guess that's not going to work. On to the resister plan.