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GMC Yukon Denali/XL Autoride Suspension



  • jdkejdke Posts: 1
    Thanks for the posts! The automatic leveling stopped working on my 02 Denali. I read these post, trouble shot, ordered a new pump from Arnot and all is good! The only problem I ran into was two of the screws that hold the pump broke when I was trying to take off the old one. Thanks again to all who posted about this problem.
  • mag44mag44 Posts: 32
    New to posting here but wanted to share something, I recently decided to replace my rear shocks on my 2002 Denali, I knew both had holes so I went to Arnott, great company, prompt service, great product. I knew that just replacing the shocks probably was not my only issue since I hadn't heard the compressor run in quite a while. So after the new shocks were in nothing happened, I checked the red wire going into the compressor and there was not power, So I started back at the beginning, check the Stud 3 fuse, IGN 3 and RTD fuse, all good, bench tested the ALC compressor relay, good. Tested the level sensors on each wheel they were good. Bench tested the compressor by putting 12 V on the red wire and the it ran fine. So now there are only two things left that can cause a issue. The exhaust solenoid & the pressure switch. The connector that connects the compressor to the truck only has supply power (Black & Red wire) for the compressor, takes the signal from the exhaust solenoid (blue & white wires) and the pressure sensor (orange, green & yellow wires from the compressor to the ESC Electronic Suspension Module which is located on the right rear side of the Denali accessed from the inside under the side panel. So to test the exhaust solenoid, I put the compressor back in the truck on the cable that connects to the compressor I striped about a 1/4" of wire from the Blue & White wires before it went to the compressor. I turned the key on and then jumpered across the two wire, the compressor turned on as it was suppose to. So I knew that exhaust solenoid was bad. If you look on the compressor the blue in white wires are attached to a small plate with two screws, inside that is an induction coil when energized make a magnetic field which operates a small plunger inside the coil.

    Of course no one sell just that part, but before you buy a new compressor for a $10 coil here's what you need to check. To make it easier, It I took the blue and white wire out of the connector so I could just handle the solenoid. Use a utility knife and cut the expoxy of the top of the plate, Place the solenoid into a vise just so the vice is holdig that top plate. I put a small screwdriver between the two ears that project up on both side and slightly tapped the metal shroud out. Once out the you will see the plunger and spring in the center. The coil is wrapped in a blue tape remove the tape and expose the terminals where the 12V is supplied. The coil is wound with a hair width wire that on mine was broken off from the terminal. I resolder the wire, bench tested the coil by giving it 12V, took a paper clip inserted inside the coil and it snapped to the coil telling me the magnetic field was working.

    As they say, reverse the steps to put it back together, I just used a good expoxy to seal the top again.

    Put the system back in and every is running fine.

    Sorry for the long post but this took a total time of about 30 minutes to test and fix so I hope it saves someone else a couple hundred bucks too.
  • dbrown6dbrown6 Posts: 4
    That is the first reasonable fix I have heard. I'm going to do it before I head out on vacation. I have an 02, it just quit, the shocks are in good shape, fuses all good etc... Thanks.
  • mag44mag44 Posts: 32
    Good Luck, let me know how it goes or if you have any questions. I'm sure a lot of people are buying new compressors because of this little problem.
  • svigilsvigil Posts: 5
    i have a 2004 Yukon XL denali and the rear shocks have a leak. i purchased some Z55 replacements from Napa. I have the following questions:
    Do I have to replace all 4 shocks at the same time?
    Is there any special installation requirements i most follow prior to installation?
    Once i have replaced them is there anything I else i must do?
    thanks for your help
  • mag44mag44 Posts: 32
    In Regards to the Exhaust solenoid, I kinda forgot a minor detail that takes the guess work out before you disassemble the solenoid. You can Ohm out the Blue & White wires inside the connector first, after I repaired mine it registered about 21 Ohms. Before I repaired it, the readings fluctuated and was not stable. I guess it's also possible that the wire can break off and still lay across the terminal which may give you a reading until it shakes around.
  • mag44mag44 Posts: 32
    I am not familiar with the Napa replacements but they look like a direct swap. So it should be easy, Jack it up, take the tires off (it makes it easier), unbolt the top and bottom, disconnect the two connections and put the new shocks in. There's really nothing special you need to do before or after. Just tighten up the bolts and put the two connections back on.
  • ukondoitukondoit Posts: 27
    With 120K miles on my 2004 Yukon Denali (which has level ride and Stabilitrac) I've replaced the Rear Shocks and Compressor and now it's time to replace the front shocks. I'm just wondering if I should go with AC Delco OEMs on the front or the Billsteins. Not sure if I like the idea of having to trick-out the computer with the Billsteins so that it doesn't throw errors. OEMs are still avail for about $600 for a pair and Billsteins are about $380 for a pair. To match the shocks or not. That's the question. Any ideas? :confuse:
  • ukondoitukondoit Posts: 27
    TAZZ1037 - Does your truck have Stabilitrac? All wheel drive? Just curious if the this would be a probelm if I installed Bilsteins on the front. The rear already has replacement ACDelco OEMs. What kind of truck do you have?
  • ukondoitukondoit Posts: 27
    Regarding Bilstein Shocks - Arnott says "Our new exclusive design connects to the auto-leveling system with no modifications. Includes sensors to plug into the auto dampening control unit to eliminate any error messages on your dash. "

    Does this mean the the built in auto-dampening system is disabled???
  • mag44mag44 Posts: 32
    Yes, with the Arnott shocks you have to cut and splice their sensors into the system.

    I do have to say that I am still receiving the "Error Message" even after doing this. I am working through the issues with Adam Arnott currently. I only asked for his help late Friday and he has responded quickly on Saturday but me being a dumb*&% I forgot to tell him what I was installing them on, so I am sure I will hear from him shortly. I will keep you posted once the message goes away.

    My thoughts on the shocks, I have 135000 miles, and the cost savings over the auto dampening was not that important to me. If you got the cash and want to spend it go for the direct replacements. I still have a kid in college!! That is why I do not have a new truck yet!! Got one out & One to Go!! $26K savings a year should buy me a nice new somthing in 2 years.
  • ukondoitukondoit Posts: 27
    mag44 - Thanks - Keep me posted - I wish that Arnott had the OEM fronts still in stock. I just think that I'd like to keep the shocks matched and don't want to screw around with the electronics. Let me know what Adam comes up with.
  • lia0824lia0824 Posts: 1
    Hi all, Purchased an 02 denali xl with 95k miles on it. Hooked camper up and the back sunk. Took to dealer and they diagnosed (for $89) that it is the compressor. (I knew it had to be somehthng like that because I had no problem with our 00 suburban). They are trying to charge me 2 1/2- hours for the install. 1 hour for diagnosis (which I already paid for) 1/2 hour for the install and 1 hour for programming. Nobody has discussed programming. When I first called the dealer about us putting it in ourselves they said "oh no, its very dangerous". Obviously (with the awesome help of this forum) I'm not being told the truth. I ordered a new compressor from an oem distributer online for $350 (dealer wanted list $500+). Questions are: How hard is it to install, where can I find instructions, and how long does it take? Also why would they tell me it needs programming? THANKS!
  • ukondoitukondoit Posts: 27
    It takes a newbie about an hour to install. The OEM version (unlike the Arnott pump) comes with the dryer, I believe, which makes it even easier to install..... Plus it should just plug in with no wire splicing. The dryer is just a cylindrical can. On my 2004, I pulled the left wire tire and found the compressor sitting on the left side of the axle housing. I don't know of any programming BS that needs to be done. My dealer wanted $900 for the pump. The $179 Arnott pump works great.
  • ukondoitukondoit Posts: 27
    Once you get it back together again, make sure the shocks are not leaking air. If the pump continues to run all the time, then you have a leak. If you need replacements, by the remanufacturered OEMs for about $380 a pair from Arnott Industries, or the Bilsteins.
  • mag44mag44 Posts: 32
    It takes about 5 minutes to pulled down the old compressor but since you have not done this before I give yourself

    Right behind the rear Driver's side wheel you will see the compressor housed in a small compartment protected by a flexible rubber shield. Remove the plastic push bolts and drop that down.

    There are three torx screws holding the compressor in place. Remove those, the one also has the ground wire attached to it for the compressor. Once you remove those the compressor can be wiggled down, if they haven't dropped out yet they will, there are three spacers, one for each screw, you will also see a black tube about 3/8" dia. attached to the bottom of the exhaust solenoid, just pull that off. Then there will be another black connector with a wire snap ring on the back side of the unit , rotate that wire ring 90 degrees and pop that connector off. The last thing to disconnect is the main electrical connector, if you look at it there is a push button that need to be depressed and then the connector slides apart. This is the hardest thing to do since is almost a one handed operation.

    That's it, the compressor should be out.

    To put it back in and to make things a little easier, I loosened the "Click" connector that holds the 3/8 tubing, then you can get a little more play in the line to make reinstalling it easier, you will see what I mean once the compressor is out.

    TIP: The connector with the wire snap ring can also be disconnected if your looking at the rear tire like you are going to change it, you can acutally see this connector from that position, and can easily reach in an disconnect the tube.

    To reinstall I put the 3/8 tubing on first, then the connector with the snap ring and then the main electrical connector. after the compressor is back in you can reach around and take up the slack in that rubber tubing and "Click" the snap back together. Then just screw the 3 screws back in with the black spacers, don't forget the ground wire and your done.

    No programming involved, there are no computer chips, modules or anything that needs programming. The guy that told you this is an idiot and if I had to I would find a reputable mechanic form now on.

    You can also save some money by going to Arnot Industries, they sell the compressor for $179 shipped but you will have to use your own exhaust chamber.

    I would also bench test the compressor with 12 V (Hook 12 V to the Red wire and ground to the black inside the connector) if it fires up and runs I would look at my previous post on how to check the exhaust solenoid (Ohm out the Blue & white wire in the connector, if you do not get a constant reading or it flucuates, it's the problem) which is the problems most of the time. You can save yourself a few hundred bucks.

    I hope this helps.
  • mag44mag44 Posts: 32
    While I am on here I thought I give a final update, I install the Arnott shocks and sensors required for the installation but I was still receiving the Error message. I emailed Arnott last Friday, late in the day PST. Saturday I received and email form Adam Arnott asking a couple question...over the course of a couple email and even on Sunday Adam was still emailing some check and we determined that one of the new sensors did not ohm out properly and was causing the issue. Monday morning first thing, received and email stating a new sensor was shipped. That's great service!
  • ukondoitukondoit Posts: 27
    Mag44 - Thanks for the update.
  • veladudeveladude Posts: 1
    I defitnitely have to change my rear shocks.Im ordering them from Arnott next week, i pull a trailer and the shocks are shot, im hoping the compressor is still question is can I install regular type shocks in the front ( ie monroes ..shocks u can buy at sears or most auto supply stores) or do they also need to be replaced with the autoride type shock?
  • ukondoitukondoit Posts: 27
    Mag44 - How did you make out with the Bilsteins? Ride OK? What kind of truck do you have? Denali?
  • mag44mag44 Posts: 32
    Hi Uk, So far so good, really no concerns, I have a 24" Enclosed trailer that I pulled loaded right after I installed them and the couldn't tell any difference in the ride over the OEM shocks. Truthfully, I didn't notice any concerns either since the auto dampening is disconnected which I can't imagine most of us couldn't tell the difference one way or another when pulling a load on these smooth California Highways. If I ever notice a difference and start to complain, I'll just jump into my 96 F350 Crew Cab, then the Denali ride will feel like floating on air again. I have a 2002 Denali XL. Now on to the next problem my EBCM module in my 2003 Vette is throwing an error message. Always something!!
  • ukondoitukondoit Posts: 27
    Thanks Magnum! - FYI - Having been on black ice while dodging two vehicles that pulled out in front of me, I must say that I'm sold on the stabilitrac system and I just could not see myself going with aftermarket shocks that have a manual dampening system. With the wheel sensors, and computer controls, the Denali knows when it's in trouble and the electronic dampeners control pitch, yaw or roll factors by managing the rebound and compressions strokes. The shocks also control the dampening characteristics based on the speed of the vehicle. After watching some of the video on stabilitrac testing and remembering my own experience, I have to say that I'm sold on the Denali OEM's.

    I did want put out a caveat for anyone that might be considering ordering parts from GMPARTSDIRECT.COM. Do your own research and look on the web for other reviews, but may find a purchase as a risky transaction. Ordinarily, I could get Arnott to send shocks for about $12 from Florida to Northern Virginia, but GMPARTSDIRECT.COM wanted to charge me $173 for Shipping and Handling. They don't specify how they are shipping and on their website the FAQs say that the difference pays for their staffing costs and the website cost. Isn't that part of their overhead that should be included in their base pricing? Sure it is. This is IMO may be questionably unethical and I hope that the state of North Carolina and/or other organizations call them on this. Due to a lot of the less than favorable blogs and reviews, I elected to go with my local dealer who offered a reasonable discount on this large purchase. has a very strict policy on returns. (forgitaboutit!). :mad: I also have a policy of never purchasing from any website that does not clearly have a physical address and telephone number. You cannot call these folks and there's no reasonable guarantee as to when you may receive your parts. Caveat Emptor folks.
  • dryedrye Posts: 4
    I found the compressor and tested it, it is good, need to know what activates it, where it is located and how to test it?
  • mag44mag44 Posts: 32
    If you bench tested the compressor and it worked fine then there are a few things that control whether or not the voltage is being sent to the compressor while in the car. The first and easiest item to test is the Blue & White wires that goes into the connector from the exhaust solenoid. This is the part that fails the most. You can either Ohm out the wires and see what you get for a reading, you should get a value of some sort, I think mine is about 24 ohms. This should be a constant reading, if it flucuates or no reading at all then it's bad and it's probably your problems.

    Please refer to a previous post ( June 9th) I did on how to repair it easily, I also wrote another way to test the exhaust solenoid in that post which is by jumpering across the Blue & White wires, After you jumper and turn the truck on and the compressor starts that confirms the solenoid is bad.

    The things that control the auto leveling are:


    Exhaust Solenoid (On Compressor)

    Pressure Switch (on compressor with 3 wires)

    Level Sensor at each wheel ( disconnect and rotate the arm and you should hear a faint beep to tell you they are working.

    ESC-Electronic Suspension Control Module (Located inside the passenger side rear panel inside the truck) I believe this hardy every fail since there is very little information anywhere on the web about this thing but if it does it's about $900.00 at the dealer.

    ALC Compressor relay (Located outside the fuse box compartment, engine side in a huge cable of wires-Grey. This can be bench tested.

    3 Fuses:
    RTD Fuse 30A;
    IGN Fuse 3A;
    STUD #1 Fuse 40A.

    Good Luck.
  • dryedrye Posts: 4
    Jumped out the blue and white wires, turned on truck, compressor kicked on for about one second then stopped, repeated 3 times same result. Looked inside solinode under blue tape, my wire seams ok, coil was produceing a magnetic field also.Was the compressor suppose to stay on? Also thank you so much for the help.
  • mag44mag44 Posts: 32
    First, on start up the compressor only kicks on for a short time, mine runs for about 5 to 10 seconds maybe a little longer then shuts off. This is normal.

    Hmmm.. if the compressor runs when jumpered but the wires (Exhaust solenoid) were OK too I am wondering does it run now with no jumper?
  • dryedrye Posts: 4
    checked that too, wouldn't run without the jumper.
  • mag44mag44 Posts: 32
    Here is the last thing I would check with the exhaust solenoid since it runs when jumpered and doesn't when not, OHM out the coil and see if you have a constant reading, I think mine was about 25 Ohms, if the coil wire has a break somewhere besides the actual connection point where they are soldered to the Blue & White wires your reading should flucuate, it may start out at that and then decrease and bounce around.

    I would also make sure that the connection through the connector is good when connected by checking the continuity.

    If it's neither one of those, there is a small orange O ring at the bottom of the plunger is that still on there?

    If it ohms out ok, continuity is good throught the connector and still does not work unnless it jumpered then I'm stumped,
  • dryedrye Posts: 4
    Was running out of time, had a new compressor shipped express, got it installed sat., it now works great. Thanks for all your help.
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