http://www.cadillacforums.com/forums/ca ... speed.html
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Check that out! I didn't even think of this. It was always known that you could put in a certain resistor at each shock harness but this is a much more sophisticated way to disable the system. Using the Tech 2 you can program the IPM (and probably rear integrating module) to tell it that the car does not have an ESCM which means no F55 MRC and no air compressor. That is really cool and at least is an option for someone who may not wish to keep those systems.Too expensive to repair and not a good option to have in Michigan - the magnetic ride control and air leveling. I bought the car from my son (It was a control test vehicle at his place of work) 36000 miles and beautiful condition except the rear suspension was shot. I moved the air compressor assembly into the trunk area (I lengthened the 4 wires) and was going to cheat the system after replacing the rear shocks with passive ones. By the way, a 18 - 19 watt 12 volt light bulb # 921 has a cold resistance of 1.2 ohms...would have been a perfect dummy load for the cheat on this system. I should mention the 2006 sts service manual is available from a British website for about 28 dollars. (250 mb download, 12 thousand pages long) But...then I decided to go a different direction. I pulled the fuse for the escm (electronic suspension control module) it's under the rear seat on the drivers side. Suspension error went away but still speed limited to 80 plus a new code generated. (The car saw there was a missing module.) After some research I determined the F55 option needed to be removed from the insturment control panel module (which is backed up by the rear integration module...anyway...) I got tired of begging for help so I bought my own Tech 2 scanner (Chinese clone and mine works very well!) 400 dollars delivered including the GM software and the Candi unit (which is needed for this vehicle). To get the car into "ignition on - engine off" mode you need your fob with you, and press the accesories under the start (don't touch the brake, ) and hold it for five or six seconds. With my tech 2 plugged into the port under the dash I went to vehicle systems and pretended to install a new IPM (instrument panel module) - all the options in the car appear and in the last column you can toggle the option "on" or "off" I deselected the F55 and saved... "programmed successfully" I was able to read and clear all the other codes in the vehicle except the airbag ones, (still working on that) I was astounded and so pleased! Magnetic ride is gone off the dash display over the radio and the speed limit is gone. I should mention the electronic suspension module has to remain in place plugged in because there is data lines that are hardwired through it (car won't start if you try to take it out.) but I did remove the air compressor it gets to rest in my garage. I know a lot of people have been grinding their teeth over this problem. I asked a local Buick dealer to help me and he was afraid...(?) and one local Cadillac dealer said "we can't do that at the dealer level" (b.s.) Now I am not beholden to anyone and I have a handy tool. Couldn't see letting a 4.6 320 hp north star be hogtied by anything.