Ok so I have a hummer h2 with factory air suspension. I’ve replaced the bags and the compressors , but nothing is working. Do I have to get gm to flash it or calibrate it or what ?

 

they might have disabled it unless it worked before the repair. did you check the fuses and the relay. the ride height sensors probably will need calibration once it is running.

 

fuse is good but dash still says service sire suspension and yes the air suspension worked before but the bag had a hole and the compressors died . Do I obd2 the codes away?

 

you can try erase or reset it if your scanner interfaces with the air ride. i think if you go from the single pump to the latter double pump it does need reprogramming.

 

Ok I’ll try when I get home. And I have 2 pumps befor to . Gm has to make everything complicated

 

Record the DTC codes before resetting, its important to know what the issue is and which one has been set. The are over a dozen DTC's related to the air-suspension such as:-

B2795 Suspension Control Select Switch Circuit
C0563 ROM Checksum Error
C0569 System Configuration Error
C0626 Left Rear Position Sensor Circuit Range
C0631 Right Rear Position Sensor Circuit Range
C0660 Level Control Exhaust Valve Circuit
C0696 Position Sensor Over-Current (5V Supply)
C0702 Level Control Accessory Valve Circuit
C0707 Excessive Compressor Activity
C0711 Level Control Air Pressure Sensor Circuit
U1057 Lost Communication withe Eelectronic Suspension Control (ESC) Module
C0712 Level Control Compressor Relay Circuit
C0713 Level Control Compressor Overtemperature
C0716 Left Rear Solenoid 2 Circuit
C0717 Right Rear Solenoid 2 Circuit
C0718 Level Control Compressor 2 Overtemperature

If you haven't changed the AS Module or adjusted/changed either of the ride-height sensors you should not need to recalibrate.

I'd be tempted to double check the compressor wiring and make sure the AS Unit chassis is connected to ground as well as what bronxteck has already suggested.
Check the main connector which you probably unplugged in order to service the unit.

If you can't hear any activity it sounds fundamental.

 

I checked everything . There were no code just says service air suspension. I couldn’t find the relay that I heard was on the frame . I brought it to gmc Dealer this am. I’ll post what they find when they call me . Hopefully it’s just a relay or a bad ground

 

It may be that 3rd part OBD2 Diagnostic scanner may not be able to access all DTC codes, its unlikely that you'll get a "Service Air Suspension" without a code being set.

A TECH2 scanner will work, the GM dealer should have one.

 

Agreed - as far as I know, there is no aftermarket code scanner/reader that can access the AS module. Only a GM Tech2 can access that particular module.

The main relay for the compressor is on the firewall under the brake hydroboost/brake reservoir...

 

your 100% right . They had to use a TECH2 scanner to erase the code to get the compressors to start. A regular obd2 will not do **** for the air suspension. Thanks everyone for the suggestions and help