Help with air bag height adjustment

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
so i replace the air bags on my 07 envoy denali 2wd (swb) for the arnotts gen one bag and they work awsome. my only problem is that the rear end is max out at 35 inches from the ground to the edge of the wheel well...
i found this procedure for recalibrating the ride height but im not sure what fuses to pull since on my 07 i dont see a fuse for ride (15)
has anyone recalibrated their trailvoys using this?
I found a much more practical and easier way.

BOOK METHOD:

----Turn key on for 2 minutes to let the airbags deflate (I call bs-its always hit and miss)
----Turn vehicle off.
----Remove airbag sensor fuses.
----Support frame of vehicle on jackstands, remove rear wheels.
----Jack axle up to the desired measurement.
This is goofy- it says 1" more than the numbers below
tb ss - 5.3"
Denali or XL - 6.33"
this is the "D-Height ( From top of axle to bottom of the frame )
----Hold that position, put fuses back in and start the vehicle.
----Done

Method I used that worked:
2 floor jacks are needed
----Start the vehicle.
----Jack the frame up on one side to where tire is barely grounded. Hold this for 10 seconds. Let it down. This is done to let the air out
----Quickly repeat this on opposite side. (You can do both sides at once)
----Wait for vehicle to deflate.
----Turn vehicle off.
----Remove airbag sensor fuses
----Found a common area from flat level floor to bottom of link perch to measure.
----Jack vehicle up on both sides to your desired height. Hold.
----Reinstall fuses. Turn ignition on-not vehicle. wait until all indicators stop flashing.
----Start.

Thats it- worked for me and took all of the guesswork out. What I would recommend for anyone lowering or lifting is to know what it sat at from the factory (center of wheel to bottom of fender, or anyplace where a solid and reliable measurement can be made) For instance, if you wanted to lower the rear 4 " you would simply get the vehicle to normal ride height and before it deflates the rear take your reliable measurement. Then, follow the instructions above and decrease that measurement by 4". DONE.
It would be nice for a few people to post there factory measurement while at normal height. I guess we would only need a tbss and add an inch for whatever else. (I know this measurement is posted a billion times, but I personally dont like measuring from center of the wheel. A level floor to a point on the frame seems easier to be exact) I took a test drive and *after* I got out of vehicle with ignition off I measured again. Exact to the 10th of an inch. Again, sorry if I over looked this posted somewhere but I had post because I know what a pain this is and this worked for me with ease.

note: the reason for doing it this way is so you dont mess with the sensors....at all! Pulling the fuses and reinserting them recalibrates (memorizes) the new position. It is helpful also if you have moved the sensors because the sensor location does not matter when it is reprogrammed. However, I do recommend moving the sensor to a close to factory location, if they have been moved, before programming so the distance of travel is a safe amount not to bind the sensor arms (plastic).
 

littleblazer

Member
Jul 6, 2014
9,267
I mean I don't know if it's different on the 360s but on the escalade it would be far easier for me to simply move the sensor. Iirc it was visible with the car on the ground. I'm not seeing how it can self calibrate since it uses the sensor as a toggle unless it is looking for it to be close to begin with then I suppose it works. (No doubting the method just trying to understand.) I know my truck is 18 something inches to the bottom of the receiver on level ground but I don't have air ride. Thanks for the info though. :tiphat:

P.S. I ended up ripping out the air ride in the escalade because it kept failing. Ride is just as good imo.
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
Same here. Although my bag system has been replaced with springs, seeing the system, I would imagine adjusting the sensor would be far easier.
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
i did take the bags out last year before winter here in pa because the cold weather does affect the system so to save the compressor i pull the ecas fuse and put xl spring for the winter, did the same this year as well since and this time somehow i cant get the system to recalibrate

i know the air rideis independent from the can-bus system and as long as i can get the emos to clear the previous settingit will take the currentsensor reading at a set height to be the "new" baseline.

on the escalades its a lot more simple as it has air shocks helping the springs vice airbags, at least in the 06models
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
im pretty sure that i could adjust the sensor manually but it would be nice to not be necessary to touch them unless i have to. plus learning the new way to calibrate the sensors will be more practical for me. i dont use the truck much but most if the times i use it is to pull my small enclosed trailer with bag and gear( around 4k loaded)
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
just because I'm stubborn and I know there is a TSB to preform this procedure without messing with the sensors [TSB # 06-03-09-006B (Dec 2008)] here is what I'm trying this weekend
somehow the sensor signal gets ing power for the 4WD fuse. mine is a 2WD as so there should be no reason to actually have a fuse in #48 aside for the sensor signal.
I did the above procedure to set the height to 33 inches by just pulling the ECAS fuse and that alone didn't do it even when the height was set and the compressor did not turn on I was happy. but it was short lived because I found out that it takes 30 mins after installing the fuses because the ECAS system has an internal clock to self test after the fuse has been inserted and if you try to start the truck the compressor will not come on.

so here is my new approach
1. lift the truck by the trailer hitch and cycle the key two on fro 2 mins (X3) as this will force the vent valve to open and deflate the bags
2. pull fuse #1 (ECAS) under hood and #48 in cabin fuse box (4WD)
lower the rear to 33 inches
3.put the fuses back in
4. wait 30 mins
5 cycle the key to run and wait for the lights to go out on the dash
6. start the truck and wait 5 seconds that is what it normally takes for the compressor to kick in after start
7. let it run and measure the ride height after the compressor shuts off

more to follow....
 

northcreek

Member
Jan 15, 2012
3,346
WNY
Is all of this because you used the Arnott Gen 1 bags? I replaced mine with OEM bags and they were just plug n play.
I've got an OEM compressor unit waiting in the wings and I'm hoping that it will be the same. Mike.
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
Is all of this because you used the Arnott Gen 1 bags? I replaced mine with OEM bags and they were just plug n play.
I've got an OEM compressor unit waiting in the wings and I'm hoping that it will be the same. Mike.
I think is a combination of the arnott gen 1 bags and the monrow reflex shocks i installed that kept settling at 35.5 inches in the rear.
i did this last night, setting the right hight from floor to bottom of wheel well to 34" and so far so good. so as it is now the front sits at 33" and the rear at 34". but i will like to see the rear at 33" and then hook my trailer up and see if i get into the bump stops at 33" inches on the rear.
this being my second set of arnott bags i use i trust their products. i only replace the other ones with under 6k miles on them just because i had a new set in the garage that i was planing on using on another project so i will be usung the used ones on that (air bagging the trailer).

im surprised my compressor has never giving me any problems, although i normally replace the valve kit every 3 or 4 years or so, i bought about 5 or 6 of the rebuilt kits for it and still have a 2 left, but they are getting harder to find online so i might have to get a handful more to keep around just in case.
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
well this is definetly the easiest way to adjust the rear air suspension, did it 2 days ago and im holding the rear end height at 34" and doesnt bottom out with the trailer attached. a lot easier than trying to adjust the height sensors for sure.
 

Boricua SS

Member
Nov 20, 2011
3,080
Ohio
adjusting the sensor is way easier than what was stated in earlier posts but to each their own... luckily the SS wheels have the big gaps in between the spokes of the wheels to where you dont have to jack anything up. I just reached in, took out one 10mm bolt from the sensor mount... done... lowered to 30.5" ground to the fender lip... literally less than 5 minutes and i was lowered. But good to see other options out there for folks wanting to go a different route.
 

RiccoH

Original poster
Member
Feb 27, 2017
12
Haines City, FL
i wish i could go to 30.5 inches in the rear, but that will be with the airbags deflated sitting on the bump stops hard no my envoy. that will be unplesant pulling a trailer.
 

j-bone

Member
May 5, 2014
83
hi i realize this thread is old but I found it useful going to try and calibrate mine tomorrow as ive been chasing my tail for a few months .
it wouldn't pump up leaving it ridding on bump stops and on the rare occasion it did pump up it would go all the way up to maximum.
the sensors don't change resistance as one would thing like a tps does as I originally thought, rather it uses pwm to detect the sensor position so checking a sensor is nearly impossible, i guess if it shows a short or no resistance then its bad . I bought new dorman sensors and both of them behave this was as well as the stock ones I removed .
the service manual says the resistance can be 75-100 ohm .

Also the manual from mooseman ( not bashing him) under air suspension refers to the D height and how to calibrate it in the "suspension general diagnosis" but that file is missing that's how I ended up here
also from what I gather if you disconnect the battery the sensors have to be calibrated if the suspension drops from the ride height which i think is my problem as I replaced the battery a few months ago and its possible the height dropped over the day it took to get a new batter in .
 

07saab97x

Member
Jul 19, 2015
11
It seems absurd that there is not one definitive ride height like the older Town Cars and some Crown Vics had. I just wasted $1k (long story, chasing a sound that’s still there!) for Arnott bags and a Dorman compressor (nothing wrong with the old bags or old compressor but oh well). So now the ride height seems a bit higher than when Chevy replaced the bags at around 150k in 2017 but pix I have of the vehicle from 2015 which seems to show a higher ride height, similar to most of the few left on the road 97x’s I see. So where is the proper measurement taken and what is the number? Thank you
 

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northcreek

Member
Jan 15, 2012
3,346
WNY
I would just adjust the two level sensors until you get it to the level that you desire. With aftermarket bags and compressor the factory settings probably go out the window... :twocents:
 

Mooseman

Moderator
Dec 4, 2011
25,671
Ottawa, ON
GM's normally come from the factory with a slight rake so if that's what you want, adjust it for that, if not, then adjust for a flat ride. What you really need to measure is side to side to ensure it's even.
 

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