GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The suspension control module provides a common ground (low reference) for all four of the shock solenoid valves. The suspension control module monitors the return voltage on the low reference circuit (ground) for a voltage out of range condition.

Conditions for Running the DTC

Continuously with the ignition on.

Conditions for Setting the DTC

The suspension control module senses a low reference voltage out of range condition.

Action Taken When the DTC Sets

    • Disable all shock solenoid valve outputs.
    • The "SERVICE RIDE CONTROL" message will be displayed.
    • Stores a DTC C0690 in the suspension control module memory.

Conditions for Clearing the DTC

    • The suspension control module senses the correct voltage on the low reference circuit upon the next ignition cycle.
    • Using a scan tool.
    • A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Diagnostic Aids

The following conditions may cause a malfunction to occur:

    • An open in all 4 low reference circuits of the shock solenoid valves.
    • An open in the solenoid ground circuit at the suspension control module.
    • An open in G410 or SP410.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests whether the condition is module, system, or condition related.

  2. Tests whether the condition has been corrected or identified as specified in the supporting text.

  3. Tests all 4 low reference circuits of the shock solenoid valves for an open.

  4. Tests all 4 control circuits of the shock solenoid valves for an open.

  5. Tests the solenoid ground circuit at the suspension control module, should be less than 0.5 ohm.

  6. Clear DTCs and checks to see if DTC will reset.

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the RTD Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Real Time Damping

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 C0690 in the suspension control module.

Does the scan tool indicate that DTC C0690 is current?

Go to Step 4

Go to Step 3

3

Since most occurrences of this DTC are caused by connector C197 not fully seated, backed out or bent terminal.

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

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

Test all 4 shock solenoid valve low reference circuits for an open between solenoids and the suspension control module. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Test all 4 shock solenoid valve control circuits for an open between solenoids and the suspension control module. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Disconnect the suspension control module connectors.
  3. Test the resistance of the solenoid ground circuit at the suspension control module, should be less than 0.5 ohms. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

8

Important: After replacement, use the scan tool to perform the set up procedure (re-calibrate) located under Special Functions (F8: Recalibration) for the suspension control module.

Replace the suspension control module. Refer to Electronic Suspension Control Module Replacement .

Did you complete the replacement?

Go to Step 9

--

9

  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 2

System OK