GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 DeVille 🢒 DTC 🢒 DTC C0690, C0691, or C0693

Circuit Description

Battery voltage for the strut actuators is supplied to the Electronic Suspension Control (ESC) module through the damper drive relay circuit. The ESC module energizes the damper relay by opening and closing an internal ground for the damping relay coil control circuit. The ESC module monitors the damper drive relay circuit and each strut actuator high-side and low-side drive circuits for fault conditions.

Conditions for Running the DTC

The Ignition is ON.

Conditions for Setting the DTC

DTC C0690

The following conditions must be present to set the DTC:

    • The ESC module detects voltage less than a preset value in the damper drive relay circuit during a damper relay valve OFF state test.
    • The fault is detected during three consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with a scan tool.

DTC C0691

The following conditions must be present to set the DTC:

    • The ESC module detects a loss of voltage in the damper drive relay circuit.
    • The fault is detected during three consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with a scan tool.

DTC C0693

The following conditions must be present to set the DTC:

    • The ESC module detects voltage greater than a preset value in the damper drive relay circuit during a damper relay ON state test.
    • The fault is detected during three consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with a scan tool.

Action Taken When the DTC Sets
    • ALL the strut actuators may be disabled by commanding 0 % PWM duty cycle.
    • The vehicle ride will be soft.
    • The vehicle speed will be limited.
    • The SERVICE SUSPENSION SYS and SPEED LIMITED TO XXX messages will be displayed.

Conditions for Clearing the MIL/DTC
    • The scan tool can be used to clear the DTC.
    • The DTC is saved as history when the ESC module no longer sees an out of range feedback voltage in the damper drive relay circuit. The DTC will clear if the fault does not return after 50 consecutive ignition cycles.

Diagnostic Aids

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

Test Description

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

  1. This step tests for voltage in the damping relay coil control circuit.

    2.

  2. This step tests for a short to voltage in the damping relay coil control circuit.

    3.

  3. This step tests for a short to voltage in the damper drive relay circuit.

    4.

  4. This step tests for an open in the damper drive relay circuit.

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Road Sensing Suspension Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Road Sensing Suspension

2

  1. Disconnect the ESC module connector.
  2. Connect a test lamp between the damping relay coil control circuit of the ESC module connector and a good ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 7

3

  1. Remove the damper relay.
  2. Connect a test lamp between the damping relay coil control circuit of the ESC module connector and a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 4

4

Connect a test lamp between the damper drive relay circuit of the ESC module connector and a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 5

5

  1. Install the damper relay.
  2. Connect a 10 amp fused jumper wire between the damping relay coil control circuit of the ESC module connector and a good ground.
  3. Connect a test lamp between the damper drive relay circuit of the ESC module connector and a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 6

6

Test the damper drive relay circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

7

Test the damping relay coil control circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

8

Inspect for poor connections at the harness connector of the ESC module. 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 13

Go to Step 12

9

Repair the short to voltage in the damping relay coil control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

10

Repair the short to voltage in the damper drive relay circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 13

--

11

Replace the damper relay.

Did you complete the replacement?

Go to Step 13

--

12

Important: Perform the set up procedure for the ESC module.

Replace the ESC module. Refer to Electronic Suspension Control Module Replacement .

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 as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK