GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2004 🢒 H2 🢒 Suspension 🢒 Air Suspension 🢒 DTC C0702

Circuit Description

During the key ON self test of the air suspension system the air suspension inlet valves, exhaust valve, and electronically controlled air suspension relay are actuated and the voltage draw is calculated by the Air Suspension Control Module.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

Air suspension module senses general valve voltage does not agree with command state.

Action Taken When the DTC Sets
    • Air suspension functionality is suspended.
    • 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 general valve circuitry is shorted to ground, voltage and open.

Test Description

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

  1. During the air suspension exhaust valve operation, listen for an audible click. Command the ON and the OFF states. Repeat the commands as necessary.

    2.

  2. Verifies that the air suspension module is providing voltage to the air suspension exhaust valve.

    3.

  3. Tests for an open in the ground circuit to the air suspension exhaust valve.

    4.

  4. Tests for constant voltage to the air suspension exhaust valve.

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.

    5. 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.

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 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 Assembly Automatic Level Control Air Replacement .

Did you complete the replacement?

Go to Step 13

--

12

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

  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?

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