Again not sure how to keep all the functions, however here is a description of how it all works.2005 HUMMER H2

Air Suspension Description and Operation

Air Suspension

The primary mission of the air suspension system is the following for the rear suspension under loaded and unloaded conditions:

• · Keep vehicle visually level
• · Maintain optimal ride height
• · The air suspension system consists of the following items:
• · Two compressor assemblies
• · Air suspension module
• · Electronically controlled air suspension relay
• · Air suspension sensors
• · Ride height switch
• · Air suspension exhaust valve
• · Air suspension inflator switch and fill valve
• · Air suspension pressure sensor
• · Air suspension inlet valves
• · Rear air springs

Compressor Assemblies

The air suspension system consist of 2 compressor assemblies. Both compressors run simultaneously and are controlled by one relay. One compressor has the exhaust valve mounted on its cylinder head. Each compressor has its own thermal limit switch. The compressors are a positive displacement air pump, powered by a 12-volt DC permanent magnet motor. A thermal limit switch protects each compressor. The thermal limit switch is normally closed and provides a ground signal to the air suspension module. If there is an over temperature condition the thermal limit switch will open and signals the air suspension module to deactivate the compressor relay. The compressors will stop running and a DTC will set. Intake air for the compressors is drawn through an intake filter and line that is attached to the fuel filler pipe in the left rear wheel area. The air compressor assemblies are mounted to a bracket that is located under the rear centre of the vehicle. The compressor air dryer is mounted next to the air compressors. It contains a moisture absorbing chemical that dries the compressed air before it is delivered to the rear air springs. Moisture is removed from the dryer and returned to the atmosphere when air is exhausted from the air springs during vehicle lowering.

Air Suspension Module
The air suspension module will conduct several self-tests at every ignition activation, while other tests do not commence until wheel speed is detected at the wheel speed sensors. During self-test if any of the module components are found to be malfunctioning a DTC will set and the tell-tale is activated. The tell-tale message that the air suspension module can display is “SERVICE SUSPENSION SYSTEM” Each DTC consists of one current and one history DTC. History codes will be cleared after 100 consecutive malfunction-free ignition cycles or with a scan tool. The air suspension module communicates with other modules in the vehicle via class 2. The levelling function will be disabled when any door or lift gate is open or when the inflator is being used. To prevent energizing the electronically controlled air suspension relay or air suspension inlet valves during normal ride motions the air suspension module provides a calibrated delay before levelling the vehicle.

Electronically Controlled Air Suspension Relay
Both air compressors are controlled by the air suspension module by the use of a relay. The relay and wiring are protected with a 60-amp fuse. The air suspension module will only activate the compressor relay when the engine is running.

Air Suspension Sensors
The rear air suspension sensors are potentiometers which detect height changes at the rear of the vehicle. The sensors relay the height changes to the air suspension module. The sensors are mounted to the frame at the rear wheel area on the left and right sides. The activation arm is attached to the upper control arms of the rear suspension.

Ride Height Switch
Extended ride height is used to increase vehicle ground clearance. When the ERH switch is activated the vehicle will raise 2 inches at the rear. The extended ride height will only occur if vehicle speed is less than 64 km/h (40 mph) with the lift gate and all doors closed with the engine running. When the switch is activated the switch LED will flash while the vehicle is transitioning to extended ride height. When the vehicle reaches extended ride height switch LED will be on continuously. The vehicle will return to normal height when the switch is activated again and the switch LED will go OFF. The vehicle will automatically return to normal height if vehicle speed increases over 64 km/h (40 mph) and the switch LED will turn OFF.

Air Suspension Exhaust Valve
The air suspension exhaust valve is used to exhaust air from the air springs and lower the vehicle. The air suspension exhaust valve is mounted on the head of one of the air compressors. The air suspension exhaust valve is controlled by the air suspension module.

Air Suspension Inflator Switch and Fill Valve
The inflator system consist of a inflator hose to provide a means of inflating objects and a switch with a LED located in the rear compartment. The inflator will only function when the engine is running and the vehicle is in PARK. The switch LED will be illuminated with the inflator ON. The inflator function will have priority over levelling functions.

Air Suspension Pressure Sensor
The air suspension system uses the air pressure sensor to monitor system pressure. The air suspension module uses that signal to determine if there is a leak in the system and to maintain minimum air pressure in the system.

Air Suspension Inlet Valves
The air suspension system has 2 inlet valves. One for the right air spring and one for the left air spring. The valves are mounted to the valve block with the air suspension pressure sensor and is located next to the compressor. The valves are activated and controlled independently by the air suspension module.

Rear Air Springs
The air springs are mounted in the frame in the same location were the coil spring is mounted for a vehicle without air suspension. Support pieces are affixed to the axle for the air springs.

 

 

After watching a couple of youtube videos heres what I did. I disconnected the relay at the front just because I was tired of the intermittent running of the compressor. I then went under the back where the tanks are and disconnected the 2 connections directly to the compressor. I taped all these up so hopefully no water damage will get in. The only thing that did was stop the clicking (3 clicks when I turned on the car from the rear compressor. I attempted to clear codes but my scanner said there were no codes to clear. When I turn on the H2 the service air suspension light comes on and I click the enter button and the message leaves and doesn't come back on.

I am assuming by disconnecting the power I have rendered the compressor useless? I have debated on just taking the assembly out but looks like some wiring harnesses are connected to the side of the tray so I don't want to mess with it either.

Its better but I don't want to screw anything else up lol.

 

 

Almost all consumer scan tools have all of the standard vehicle functions but do not have the ability to see special manufacturer specific modules like the air ride module which is why you are not seeing a trouble code to clear. You would most likely need a Tech 2 (or newer MDI) to access and clear codes on things like that. A Tech 2 also lets to you deflate the system for service, calibrate the height, etc as well as other things like clearing out old key fob programming, very specific system testing like the instrument cluster, and whatnot.

I know many have removed the air ride and got the message to go away but I'm not personally sure of what the steps are.

 

Ok one last update for now. The last think I did was disconnect the negative terminal of the battery this morning after disconnecting the relay and the power to the compressor after reconnecting the negative the message was GONE!. I left it tun for about 20 minutes and it never came back on. I'll post if that changes. Now I want to decide if I should hook the compressor back up I guess to use it for airing up tires although I never have. Didnt seem like it worked well when I did try it.

 

let me know if it works... this is with the relay gone and you unplugged the air suspension compressor computer (whatever it is) plug too?

 

Today I totally removed compressor/receiver tank from vehicle and taped up connectors. Now to eliminate service etc etc warning. Recent purchased my 2005 H2 Lux ex Japan White 33k miles Looking for UK owners to help me gain more experience

 

yes this is correct.