Auto Ride Problem

[fyrffytr1]

I have a 2002 Suburban with auto-Ride. I bought this vehicle in Feb. of this year. The compressor that levelled the vehicle worked then but recently I have not heard it kick in and when I hooked to my 10' equipment trailer the rear sagged .

I took it to the local dealer because I was not sure what fuse to check. A service tech went out to my truck and looked under the hood in the fuse box. He pointed to an empty spot and said that was my problem. It was missing a 30 amp fuse. I didn't think he was right but went along with him. The empty spot was labeled A.I.R.

He gave me a fuse and said that should solve my problem. It didn't. Am I wrong or is that fuse used only in a diesel motor?

I read the owners manual and the only fuse I could find according to it was the one marked RTD(Real Time Dampening).It was good. What else do I need to check and is there a way to check the compressor?

[blue dave]

Thanks for the reply!

 

I found out that the compressor unit (complete assembly with compressor, filter/dryer, pressure switch & exhaust solenoid valve) that I bought in January has a 12 month warranty.

 

I simply took the unit back to the GM dealer and they gave me a brand new one. I installed it and everything is working properly again. I sure hope that this one lasts longer than the last one.

[zyrabernard]

The sensors are located near the rear wheels, under the little plastic fender lining toward the front part of the inside of the fender.

It is 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 then gives the on / off command to the pump in the autoride unit.

 

 

yours,

zyra

 

Simulation pret immobilier

[gargoyle]

I just ordered a pump from Arnott ( thanks for the link FYRCAPTAIN)

Installed it including the dryer rebuild kit and it works great.

 

Came with all the mounting bolts and rubber bushings.

 

Arnott is terrific to deal with. I recieved it by UPS in 1 day !!

[godav]

I understand that the dealer would have the part number, but I was going to look for an aftermarket part.

Thank You

Gary

[Sink1]

I recently purchased a used 2003 Denali and noticed the rear end was sagging. I thought the owner had lowered the vehicle, but when I looked underneath, I could see one of the shocks was leaking what looked like oil. I had also noticed a noise coming from the driver's side rear tire, later identified as the compressor.

 

After much research on the issue, we purchased new OEM Air Ride shocks for the rear and put them on the vehicle with no problems. It seemed to fix the sagging issue, but the compressor keeps coming on every time I turn the vehicle on/off and it seems to continue to sag after the vehicle has been parked for an extended length of time. Air Ride shocks are completely new to us, and we are not sure if it is "normal" for the compressor to come on and off so frequently, or should we replace that as well? I have observed other Yukon Denalis in parking lots when we are out and about, and they don't sag so I am guessing I still have some unresolved issue with the suspension.

 

We really love the vehicle, and want to be able to tow our boat with it, so we really need to solve this "sagging" issue. Any advice would be greatly appreciated.

 

Thanks in advance.

[no bull]

I have a 2500, 8.1L yukon xl, and was under the impression that Level Ride had a compressor and Auto ride has electronicly operated shock valving with NO compessor (Auto Ride is on my truck). Am I wrong, do I have a compressor?

[bernarde]

Thanks again! I will attemp to check for a leak this weekend (or rather my husband will )! If that is not the problem, we'll continue to trouble shoot.

 

On a side note, after the shocks were replaced, the "Service Ride Control" message now comes up on the instrument panel, and did not prior to the shock service. Since the owner's manual explanation is hardly comprehensive, could it be possible a sensor was knocked loose when the tires were removed? I didn't think a 2003 Denali had the tire pressure sensors, but I could be wrong. Funny how this message comes on now and did not come on when there was a leak in the shock itself?

 

As always, thanks again!

 

 

 

OK...NOW maybe we are getting somewhere.

You didn't mention earlier that you were getting an error message about SERVICE RIDE CONTROL.

 

There are sensors attached to the suspension so that the compressor comes on and off at the appropriate time.

 

It is very possible that one of these got knocked loose or bent or wires got unplugged during the replacement of the shocks.

 

The sensors are located near the rear wheels, under the little plastic fender lining toward the front part of the inside of the fender.

It is 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 then gives the on / off command to the pump in the autoride unit.

 

There may be sensors that also plug into the shocks themselves...but I am not sure about that.

My experience with LEVEL RIDE / AUTORIDE, is limited to Cadillacs..but it should be similar.

 

 

 

I have a similar problem on my 02 escalade, I have a service stability system code, and the compressor runs alot. I did remove the compressor and it is in need of replacement. would the compressor running more than it should give me the sevice code or is there more to it?

[srcpqlamz]

I own a 2003 Yukon Denali. The autoride pump does not start when I put my race car trailer on it. The back of the truck drops about 3 inches. I have 22 inch rims and a good size tire on it and this causes the tires to rub the inner well when loaded. Please help as I cannot find any info on the system. I would like to try and fix the problem myself and save a few bucks.

 

Thanks

 

Kevin from Canada

 

Hi Kevin,

 

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

[jorkvilleyoe]

Here is a link for the system as a whole far cheaper than gm's prices from the supplier for gm...hope this helps...the new compressor includes the necessary kit to rebuild the existing air dryer...

 

http://www.arnottindustries.com/part_GMC_A...id15_pid95.html

[twright225]

I own a 2003 Yukon Denali. The autoride pump does not start when I put my race car trailer on it. The back of the truck drops about 3 inches. I have 22 inch rims and a good size tire on it and this causes the tires to rub the inner well when loaded. Please help as I cannot find any info on the system. I would like to try and fix the problem myself and save a few bucks.

 

Thanks

 

Kevin from Canada

 

Hi Kevin,

 

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

 

 

 

 

 

 

You can sometimes find a replacement air ride assembly on ebay. I bought one that fit a 2005 Yukon Denali and it was a perfect match for my 2001 Yukon XL Denali. My air ride suddenly stopped working at 130,000 miles. I applied 12 VDC to the Red(+) and the Black(-) wires on the 7 pin connector using a battery charger and the pump motor turned on just fine. The fault was a bad pressure switch on the dryer; it has a 3 pin connector that goes to it and sends the signal to the pump to turn off so it doesnt over pressure the shock bags. So I wish I could find a new pressure switch for my air ride assembly but can't seem to find one maybe Delphi would sell me one? Anyway I suspect that this is a very common problem with these assemblys and what could be a quick inexpensive swap of a pressure switch ends up being a $700+ air ride assembly swap at a dealer. I ended up buying the assembly off of ebay for $300 as I said above and swapped it out in 10 mins tops. Anyone know where I could get a new pressure switch for my old one?

[blue dave]

Does anybody know if I can purchase just the exhaust solenoid. I really do not want to replace the entire compressor, exhaust solenoid, dryer, pressure switch as a complete assembly again.

 

Also out of curiosity, can anybody tell me the purpose of the exhaust solenoid and when & why it is activated?

[medinab]

OK, I found the suspension control module in the passenger side rear area behind the interior panel and under the rear HVAC blower.

 

When I ground the light blue wire on connector C2 - A10 the compressor runs which tells me that the automatic level control relay and the compressor are both working fine. I never found the relay but I guesss that it is now a moot point since it is working properly.

 

So now I need to find out why the suspension control module is not grounding the C2 - A10 output wire when it ought to be (heavy load on rear of truck). It looks like the suspension control module inputs that effect this are probably the left rear & right rear suspension position sensors (C3 - A5 & A7) and the pressure sensor (C2 - B5).

 

I now need to know how the suspension position sensors and the pressure sensor inputs effect the compressor relay output. It looks like all of the sensors use a 0-5vdc analog signal. Any help would be greatly appreciated.

[medinab]

Hi guys! I found this thread on Google so I joined the site to hopefully get some answers regarding the air ride system on my 2002 GMC Yukon XL Denali.

 

I replaced the complete compressor assembly (compressor, exhaust solenoid, dryer, pressure switch) as a complete unit last year and the system has worked fine until just this week.

 

I just tested the compressor by jumping 12v onto the red & black leads and it works fine. All three fuses that supply power to the entire system (IGN 3, Stud 1, & RTD) check out fine.

 

I have complete schematics of the system which show me that the red compressor wire is energized by the automatic level control relay (contact 87). The automatic level control relay (contact 30) is fed from the Stud 1 fuse under the hood. When the relay coil is energized, relay contacts 30 & 87 close to energize the red wire which feeds the compressor. The relay coil (contact 85) has + 12v supplied by a brown wire fed from fuse IGN 3 on the left side of the dash. The relay coil is energized when the other side of the coil (contact 86) receives a ground signal on the light blue wire fed from the suspension control module (connector C2 A10).

 

My problem is that do not know the location of the relay and the module. Can anybody please tell me where these two components are located?

 

 

I have one more question just out of curiosity. The orange wire fed from the RTD fuse under the hood is connected to one side of the exhaust soleniod coil. The other side of the coil is connected to a dark blue wire fed from connector C2 B5 on the suspension control module. My question is what is the purpose of the exhaust solenoid (purge water vapor?) and when does the suspension control module turn on this solenoid?

[medinab]

I found the main relay. It's under ther hood, attached to the side of the fuse box facing the engine. Hard to see as it's under the wiring harness but definitley the relay for the compressor pump/autoride.

[Sink1]

Thanks for the advice. I will give that a try and I will let you know if that solves the sagging issue.

 

Since I am not familiar with these auto leveling air shocks, is that normal for me to hear the compressor go on and off as though it is conatantly "leveling" the vehicle every time I turn it on and off?

 

Thanks for the help.

 

 

If there is a leak..then yes, it would be normal for the compressor to come on every time you start it.

It is just doing it's job and leveling everything back up.

 

If you DO NOT have a leak...then we need to explore other things, but I am betting on a small leak. They can sometimes be hard to find.

 

 

Thanks again! I will attemp to check for a leak this weekend (or rather my husband will )! If that is not the problem, we'll continue to trouble shoot.

 

On a side note, after the shocks were replaced, the "Service Ride Control" message now comes up on the instrument panel, and did not prior to the shock service. Since the owner's manual explanation is hardly comprehensive, could it be possible a sensor was knocked loose when the tires were removed? I didn't think a 2003 Denali had the tire pressure sensors, but I could be wrong. Funny how this message comes on now and did not come on when there was a leak in the shock itself?

 

As always, thanks again!