Hummer H2. Manual — part 2208

DTC C0563

Circuit Description

On the power-up self test, the calibration data stored in the electronically erasable programmable read-only
memory (EEPROM) is copied to shadow RAM. Data checksums are generated and verified, and the data in
shadow RAM is verified against the contents of the EEPROM. In certain situations data is written to the
EEPROM. In these circumstanced any checksums are recalculated, and the data written to the EEPROM is read
back and compared with the original data.

Conditions for Running the DTC

The ignition is on.

Did you find and correct the condition?

10

Go to Step 6

6

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

10

Go to Step 8

7

Inspect for poor connections at the harness connector of the
ERH Switch. 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

10

Go to Step 9

8

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

10

-

9

Replace the ride height switch. Refer to Electronic
Suspension Switch Replacement .
Did you complete the replacement?

Go to Step

10

-

10

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

Conditions for Setting the DTC

If the EEPROM test fails then it is repeated. If the fault is still present after 5 test cycles, then a DTC is set.

Action Taken When the DTC Sets

z

Air Suspension functionality is suspended.

z

SERVICE AIR SUSPENSION message is displayed.

Conditions for Clearing the DTC

DTC is cleared by cycling ignition.

DTC C0563

DTC C0569

Circuit Description

The Air Suspension Module monitors the trim height calibration procedure. When the calibration procedure is
activated the vehicle exhaust down to rest on a chassis support at a predetermined height. When no further
height change is detected, the height sensor readings are verified to be within 2.06 V and 2.88 V. If there are no
errors then the new trim height is accepted. If the Air Suspension Module detects any errors in the trim height
calibration procedure then the new trim height is not accepted and a DTC is set.

Conditions for Running the DTC

Ignition on

Conditions for Setting the DTC

The Air Suspension Module detects that the height sensors are not within 2.06 V and 2.88 V.

Action Taken When the DTC Sets

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

Perform the trim height calibration procedure. Refer to
Trim Height Calibration Procedure .
Does the DTC reset?

Go to

Step 3

System OK

3

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

System

OK

-

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2

The new trim height is not accepted.

Conditions for Clearing the DTC

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

Diagnostic Aids

Make sure the vehicle chassis is being supported at the proper trim height.

Test Description

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

3: Tests whether the condition is module, system, or condition related.

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

5: Test if the Air Suspension Sensors are within the proper range before the relearn procedure is
activated.

DTC C0569

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

C0569 in the Air Suspension Module.

Does the scan tool indicate that DTC C0569 is current?

Go to Step 4

Go to Step 3

3

Most occurrences of this DTC are caused by not having the
vehicle supported at the proper trim height when doing the
trim height relearn procedure.
Did trim height relearn procedure 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. Activate the trim height relearn procedure after making

sure the vehicle is being supported at the correct trim
height.

Does the DTC reset?

Go to Step 5

System OK

5

If needed, inspect the Right and Left Height Sensor voltage
reading with the scan tool to be sure that they read between
2.06 V and 2.88 V after the Air Suspension system has

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2

DTC C0626

Circuit Description

The air suspension sensor provides a signal voltage between 0.3-4.7 volts to the air suspension module. This
signal voltage represents the wheel's position relative to the body. The air suspension module provides a 5-volt
reference and a low reference to the sensor.

Conditions for Running the DTC

At power-up and continuous when ignition is activated.

Conditions for Setting the DTC

The air suspension module senses a suspension sensor voltage below 0.3 volts or above 4.7 volts.

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 clear when the condition for setting the DTC is removed.

Diagnostic Aids

This DTC is set for a high or low signal to the air suspension module from the air suspension sensor - LR.

Test Description

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

exhausted.
Did you find and correct the condition?

System OK

Go to Step 6

6

1. Replace the Air Suspension Module. Refer to Module

Assembly Electronic Suspension Control
Replacement .

2. Check the trim height and recalibrate the Air

Suspension Module if necessary.

Did you complete the replacement?

IMPORTANT:

Always check the trim height and recalibrate the Air
Suspension module if necessary.

System OK

-

2004 Hummer H2

2004 SUSPENSION Air Suspension - Hummer H2