Posted By: srcpqlmaz
I (finally) repaired my 2002 Yukon. I magine that your autoride system is identical to mine. Repair was quite simple, but costly!!! I had to change the whole Autoride unit and it costs 765$ Canadian (I live in Quebec) My dealer made me a deal, but still, I had to pay around 750$ Taxes included. The procedure for debugging and replacement is quite simple:
I located the level sensors. They are located near the rear wheels, under the little plastic fender lining toward the front part of the inside of the fender. It is just a little rod that is attached to the suspension on one end and to a rotary device on the other end. as the suspension moves up and down, the rod pushes on the rotary device. The rotation of the device will determine how loaded your vehicle is. This sensor will give the on / off command to the pump in the autoride unit. The upper part of the level sensor rod is tied to the suspension through a small ball joint. When you pull that ball joint firmly, the rod will come out, freeing the sensor. You can then manually rotate the sensor and make your autoride act like if the truck is under heavy load. When I did that, I could hear a very light noise coming from the autoride unit. When I was putting the sensor in normal position, this little noise was stopping. I did the same procedure on the passenger and driver's side and I could hear the same noise. This confirmed that my sensors were working fine and they were sending the "ON/OFF" commands to the Air ride unit. The whole air ride system is made of 3 different groups of devices: The sensors, the wiring harness and the autoride unit itself. I was quite sure that the sensors and wiring were OK. The only remaining item was the autoride unit itself. It sells as one assembly. it comprises a compressor, a pressure/dryer device and what I think is a solenoid. Only the pressure / dryer device can be purchased separately. The dryer sells for approx 350$ while the whole assembly (including the dryer) sells for aprx 765$. Since after 5 years, all the parts in the whole unit are about to die anyway, you might as well change the whole thing and avoid other problems. I'm a do-it-yourselfer, not a masochist, so I decided to change the whole unit. Changing it is easy. It is located behind the rear of the driver's side rear wheel. It is attached to the frame of the truck by 3 studs and nuts. These studs are inserted in the frame beam through 3 keyholes. All you have to do is to loosen the 3 nuts and slide the with the studs, out of the keyholes. You may need a little bit of hammering. Two of the nuts (the ones to the rear of the unit) are outside the frame beam, but the one that is toward the front, is located inside the frame beam. The genius who thought of doing that must have been smokin' good stuff! In any case, there is a hole on the other side of the frame beam that allows you to reach the nut with the ratchet (The spare tire is a bit in the way, but you can do the removal of the unit without having to lower the spare. Once this is done, all you have to do is remove the round 7 pin connector that connects the unit to the cable harness, unplug the high pressure tubing that goes to the shocks, and the intake tubing that comes from a small plastic box located inside the fender, near the refuelling hose. As they say in the haynes manuals: "installation is reverse of removal"
. The new unit comes with everything, including the little plastic box (probably an air filter) that is installed near the refuelling hose. This plastic box is tied to the vehicle through a special push pin. The pin also acts as a tube holding clamp. You know how hard these are to remove without breaking them. It may be a good idea to ask for an extra pin at your dealer. (Note to GM: at 765 bucks, you should include this push pin in the kit!) I did not ask for an extra pin... so I had to be very careful when removing the old one. I had to remove the whole fuel cap assembly to reach it. If I had had an extra pin, I would have just cut the old one and it would have saved me 30 minutes of my time.
Some other useful info: On the 7 pin round connector, the color code is:
Red and Black: Compressor + and -. My dealer confirmed that applying power to these wires will make the compressor run (if not broken of course)
Grey and blue: Going to what I think is the solenoid. The dealer told me not to apply any voltage to these wires, as it could damage the unit. I think the guy didn't know what he was talking about, but I did not take any chance anyway.
The other 3 wires (i don't remember the color) are going to the Dryer. I dont know how you can test this unit.
Part number for the whole Air Ride assembly: Delphi 15070878
P.S. My appologies if some of the instructions are not perfect. English is not my first language. Should you need more info, please do not hesitate to ask on this thread. I'll try to read it from time to time.
Stéphane
