Hummer H2. Manual - part 2212

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Air Suspension Diagnostic System 
Check?

Go to Step 2

Go to Diagnostic 

System Check - Air 

Suspension

2

1. Install a scan tool.  

2. Turn ON the ignition, with the engine OFF.  

3. With a scan tool, command the exhaust valve and inlet 

valves ON and OFF.  

Does the exhaust valve and inlet valves turn ON and OFF with 
each command?

Go to 

Diagnostic 

Aids

Go to Step 3

3

1. Turn OFF the ignition.  

2. Disconnect the exhaust valve and inlet valves.  

3. Turn ON the ignition, with the engine OFF.  

4. Connect a test lamp to ground. 

Probe the control circuit of the exhaust valve and inlet 
valves with a test lamp that is connected to ground. 

5. With a scan tool, command the exhaust valve and inlet 

valves ON and OFF.  

Does the test lamp turn ON and OFF with each command?

Go to Step 4

Go to Step 5

4

1. Connect a test lamp between the control circuit of the 

exhaust valve and inlet valves and the ground circuit of 
the exhaust valve and inlet valves.  

2. With a scan tool, command the exhaust valve and inlet 

valves ON and OFF.  

Does the test lamp turn ON and OFF with each command?

Go to Step 8

Go to Step 10

5

Does the test lamp remain illuminated with each command?

Go to Step 7

Go to Step 6

6

Test the control circuit of the exhaust valve and inlet valves for 
a short to ground or an open. Refer to Circuit Testing and to 
Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 

13

Go to Step 9

7

Test the control circuit of the exhaust valve and inlet valves for 
a short to voltage. Refer to Circuit Testing and to Wiring 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 

13

Go to Step 9

8

Inspect for poor connections at the exhaust valve and inlet 
valves. Refer to Testing for Intermittent Conditions and 
Poor Connections and to Wiring Repairs in Wiring Systems.

Go to Step 

 

2004 Hummer H2 

2004 SUSPENSION Air Suspension - Hummer H2

  

DTC C0707 

Circuit Description 

The air suspension module monitors the run time of the compressor. If the compressor has run for more than 1 
hour during an ignition cycle the air suspension module switches OFF the compressor relay. The run timer 
counts down when the compressor is OFF with the ignition ON. 

Conditions for Running the DTC 

Ignition ON. 

Conditions for Setting the DTC 

The compressor run timer has exceeded 1 hour of run time.

Did you find and correct the condition?

13

Go to Step 11

9

Inspect for poor connections at the harness connector of the air 
suspension module. Refer to Testing for Intermittent 
Conditions and Poor Connections and to Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 

13

Go to Step 12

10

Repair the ground circuit of the exhaust valve and inlet valves. 
Refer to Wiring Repairs in Wiring Systems. 
Did you complete the repair?

Go to Step 

13

-

11

Replace the air suspension exhaust valve or inlet valves. Refer 
to Compressor Automatic Level Control Replacement . 
Did you complete the replacement?

Go to Step 

13

-

12

1. Replace the air suspension module. Refer to Module 

Assembly Electronic Suspension Control 
Replacement .  

2. Perform the trim height calibration procedure for the air 

suspension module, if necessary, after check trim height 
procedure.  

Did you complete the replacement?

IMPORTANT:

Always perform the check trim height procedure after air 
suspension module replacement.

Go to Step 

13

-

13

1. Use the scan tool in order to clear the DTCs.  

2. Operate the vehicle within the Conditions for Running 

the DTC.  

Does the DTC reset?

Go to Step 2

System OK

 

2004 Hummer H2 

2004 SUSPENSION Air Suspension - Hummer H2

  

Action Taken When the DTC Sets 

z

The air suspension functionality is suspended.  

z

SERVICE AIR SUSPENSION message is displayed.  

Conditions for Clearing the DTC 

The DTC will clear when the condition for setting the DTC is removed. 

Diagnostic Aids 

This DTC is set when the compressor has run to long. 

Test Description 

The numbers below refer to the step numbers on the diagnostic table. 

3: This step tests whether the condition is module, system, or condition related.  

4: This step tests if the condition has been corrected or identified as specified in the supporting text.  

6: This step tests if the DTC sets during normal operating conditions.  

DTC C0707 

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Air Suspension Diagnostic System 
Check?

Go to Step 2

Go to Diagnostic 

System Check - Air 

Suspension

2

1. Install a scan tool.  

2. Turn ON the ignition, with the engine OFF.  

3. With a scan tool, monitor the DTC Information for 

DTC C0707 in the air suspension module.  

Does the scan tool indicate that DTC C0707 is current?

Go to Step 4

Go to Step 3

3

Most occurrences of this DTC are caused by long run times of 
the compressor. Review the air suspension system with the 
customer to verify the conditions under which the DTC set. 
Did vehicle operation cause this DTC to set?

Go to 

Diagnostic 

Aids

Go to Step 4

4

1. Use the scan tool in order to clear the DTCs.  

2. Operate the vehicle within normal operating conditions. 

Does the DTC reset?

Go to Step 5

System OK

5

Replace the air suspension compressor. Refer to Compressor 
Automatic Level Control Replacement . 
Did you complete the replacement?

Go to Step 6

-

 

2004 Hummer H2 

2004 SUSPENSION Air Suspension - Hummer H2

  

DTC C0711 

Circuit Description 

The air suspension pressure sensor sends a voltage signal to the air suspension module that corresponds to a 
pressure within the range of 30-180 psi. The air suspension module also uses this signal to verify that the proper 
amount of pressure is achieved in the air dryer within 23 seconds prior to opening of the inlet valves for 
inflation of the air springs. 

Conditions for Running the DTC 

Ignition ON 

Conditions for Setting the DTC 

The air suspension module detects that the rate of height change, central air camber pressure or the signal from 
the air pressure sensor is out of limits. 

Action Taken When the DTC Sets 

z

Air suspension functionality is suspended.  

z

SERVICE AIR SUSPENSION message is displayed.  

Conditions for Clearing the DTC 

The DTC will be active when the vehicle is moving, but then it will go to history when the vehicle is not 
moving. 

6

1. Use the scan tool in order to clear the DTCs.  

2. Operate the vehicle within normal operating conditions. 

Does the DTC reset?

Go to Step 7

System OK

7

1. Replace the air suspension module. Refer to Module 

Assembly Electronic Suspension Control 
Replacement .  

2. Perform the trim height calibration procedure for the air 

suspension module if necessary after check trim height 
procedure.  

Did you complete the replacement?

IMPORTANT:

Always perform the check trim height procedure after air 
suspension module replacement.

System OK

-

 

2004 Hummer H2 

2004 SUSPENSION Air Suspension - Hummer H2