Help me decifer this new to me Denali's autoride

[NateDiggity]

Im trying to get this system working correctly, but not sure I even know what that really means lol

I had a service suspension DIC and had the codes pulled. One was the exhaust valve that usually means a corroded wire. Found it, and replaced/temporary fixed it last night around 11pm (Had to be up by 4:30 not real thrilled)

Anyway, the compressor now fires up and runs, but didnt have time to do much testing. I did however need to verify the trailer brake controller worked since my cruise/brake switch is bad. They didnt, so thats another project.

BUT, I backed the rig under the trailer, went, had a beer, then lowered the trailer onto the hitch ball with the vehicle off. I started the yukon, got all excited when the compressor kicked on, ran for a bit, 30 seconds maybe? but never seem to actually lift or level the truck. Thats not normal correct? Usually the compressor has enough balls to pump enough PSI to level the yukon even under heavy loads? (Its actually a pretty small RV trailer considering).


What really throws me is that the rear shocks and front struts seemed to be replacements, they are label BWI though, which seem to just be an OEM supplier. With that said, they still have an air line running to them so they are non-air ride replacements. The rear coils are also replacement and with the shock still being air-ride why would they replace the coils? I was under the impression the coils were only replaced when going to non auto ride setup?


Also, something else interesting, everything I read said this body style has the compressore behind the passenger wheel, while the older body style was behind drivers rear wheel. Mine was behind the drivers rear wheel, is this an early 07 model year thing?

 

[NateDiggity]

The more I think about it I'm kind of convinced the shocks are aftermarket non air ride. That would explain why it won't air up even though the compressor is on. That would also explain the aftermarket coils, or at least not in stock. The only part that really throws me is the airlines still running to the shocks, could this be the autoride? Just not the load leveling?

 

[#1taho]

Pics will help

 

[02Lightning]

BWI are stock shocks, that is what's on my Denali and on my Cadillac CTS-V. If I get a bunch of people in the car it will kick on for 30 sec. then kick off. I’ve never really had mine squatting to see if would level out, so I’m not sure on that. Mine is a 2008 and I was just under it changing the rear diff fluid, I remember looking at the compressor but can’t remember what side it was on, I’ll have to look tonight.

 

[PatDTN]

Listening in on this. Was just under my '09 Tahoe LTZ today. It was off but I thought the system should have kept minimal pressure in the air shocks. They were clearly empty. At least in the past air shocks could be damaged running empty.

 

[Christoph559]

Listening in on this. Was just under my '09 Tahoe LTZ today. It was off but I thought the system should have kept minimal pressure in the air shocks. They were clearly empty. At least in the past air shocks could be damaged running empty.

Yes they should retain air in them

The more I think about it I'm kind of convinced the shocks are aftermarket non air ride. That would explain why it won't air up even though the compressor is on. That would also explain the aftermarket coils, or at least not in stock. The only part that really throws me is the airlines still running to the shocks, could this be the autoride? Just not the load leveling?

Do yours look like mine with the rubber bladder?

 

[Rocket Man]

Make sure the air lines actually hook up to the shocks and check for air leaks where they connect using soapy water. Also look for blown out air bladders on the rear shocks and listen for air leaking;; fronts aren't air shocks, they only have electronic damping.

 

[STORMIN08]

I would be checking for leaks...possibly even some internal blockage.

My 13, airs up and adjusts even from my body weight (250lbs.) sitting in the rear

 

[02Lightning]

Also, something else interesting, everything I read said this body style has the compressore behind the passenger wheel, while the older body style was behind drivers rear wheel. Mine was behind the drivers rear wheel, is this an early 07 model year thing?

Mine is behind the rear drivers wheel.

 

[PatDTN]

In response to Christoph559's post and the fact that mine is not holding air I looked for a description of the system and found this

http://www.underhoodservice.com/servicing-gm-autoride-rear-air-suspension/

With this in mind I'm going to see what I have now.