Hummer H2. Manual — part 2216

SYMPTOMS - AIR SUSPENSION

Refer to Air Suspension Description and Operation .

Visual/Physical Inspection

z

Inspect for aftermarket devices which could affect the operation of the air suspension system. Refer to

Did you find and correct the condition?

13

Go to Step 9

8

Inspect for poor connections at the inlet valve. 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 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 inlet valve. Refer to Wiring
Repairs in Wiring Systems.
Did you complete the repair?

Go to Step

13

-

11

Replace the Air Suspension Inlet Valve. Refer to Valve
Automatic Level Control Solenoid 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

IMPORTANT: Review the system operation in order to familiarize yourself with the system

functions.

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2

Checking Aftermarket Accessories in Wiring Systems.

z

Inspect the easily accessible or visible system components for obvious damage or conditions which could
cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

z

Inflator Inoperative

z

Compressor Runs at All Times

INFLATOR INOPERATIVE

Inflator Inoperative

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

Verify the fault is present.
Does the system operate normally?

Go to Testing for

Intermittent

Conditions and Poor

Connections in Wiring

Systems

Go to Step 3

3

1. Connect a scan tool.

2. Turn ON ignition, with engine OFF.

3. Use scan tool to activate inflator switch.

Does the compressor turn on?

Go to Step 4

Go to Step 8

4

Test the signal circuit of the air suspension inflator
switch for an open, short to ground, short to voltage and
high resistance. Refer to Circuit Testing , Testing for
Short to Ground , Testing for a Short to Voltage ,
Testing for Intermittent Conditions and Poor
Connections in Wiring Systems.
Did you find and correct the condition?

Go to Step 10

Go to Step 5

5

Test the low reference circuit of the air suspension
inflator switch for an open, short to ground, short to
voltage and high resistance. Refer to Circuit Testing ,
Testing for Short to Ground , Testing for a Short to

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2

COMPRESSOR RUNS AT ALL TIMES

Compressor Runs at All Times

Voltage , Testing for Intermittent Conditions and
Poor Connections in Wiring Systems.
Did you find and correct the condition?

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of
the air suspension inflator switch.
Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

Replace air suspension inflator switch.
Refer to Inflator Air Switch Replacement .
Did you complete the replacement?

Go to Step 10

-

8

Inspect for poor connections at the harness connector of
the air suspension compressor assembly.
Did you find and correct the condition?

Go to Step 10

Go to Step 9

9

Replace air suspension module.
Refer to Module Assembly Electronic Suspension
Control Replacement .
Did you complete the replacement?

Go to Step 10

-

10

Operate the system in order to verify the repair.
Did you correct the condition?

System OK

Go to Step 3

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

Verify the fault is present.
Does the system operate normally?

Go to Testing for Intermittent

Conditions and Poor

Connections

Go to Step 3

3

Remove the electronically controlled
air suspension relay.
Does the compressor stop running?

Go to Step 4

Go to Step 6

4

Test the relay for continuity between
pin 30 and pin 87.
Does the relay have continuity?

Go to Step 5

-

5

Replace the relay.
Did you complete the replacement?

Go to Step 7

-

6

Check for a short to battery on the
compressor battery positive voltage
circuit.
Did you find and correct the
condition?

Go to Step 7

-

7

Operate the system in order to verify
the repair.
Did you correct the condition?

System OK

Go to Step 3

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2

REPAIR INSTRUCTIONS

TRIM HEIGHT CALIBRATION PROCEDURE

1. Depressurize the air suspension system to lower rear of vehicle. Refer to Air Suspension

Depressurization Procedure .

2. Raise and support rear of vehicle at D height. 132 mm (5.2 in).

Fig. 7: Trim Height Calibration Procedure
Courtesy of GENERAL MOTORS CORP.

3. The D height is obtained by measuring the distance between the edge of the jounce cup along the jounce

bumper center line and the jounce pad on the rear axle.

4. With the scan tool perform the calibrate trim height procedure in air suspension special functions.

5. Check scan tool data list for trim height learned. Typical data value will be YES.

6. If trim height was not accepted the typical data value will be NO and DTC C0569 will set.

AIR SUSPENSION DEPRESSURIZATION PROCEDURE

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2