GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0575 01: Left Front Actuator Circuit - Short To Battery

DTC C0575 02: Left Front Actuator Circuit - Short To Ground

DTC C0575 04: Left Front Actuator Circuit - Open Circuit

DTC C0580 01: Right Front Actuator Circuit - Short To Battery

DTC C0580 02: Right Front Actuator Circuit - Short To Ground

DTC C0580 04: Right Front Actuator Circuit - Open Circuit

DTC C0585 01: Left Rear Actuator Circuit - Short To Battery

DTC C0585 02: Left Rear Actuator Circuit - Short To Ground

DTC C0585 04: Left Rear Actuator Circuit - Open Circuit

DTC C0590 01: Right Rear Actuator Circuit - Short To Battery

DTC C0590 02: Right Rear Actuator Circuit - Short To Ground

DTC C0590 04: Right Rear Actuator Circuit - Open Circuit

Circuit/System Description

The electronic suspension control module (ESCM) commands variable levels of pulse width modulated current to each damper in response to rough road, or abrupt steering maneuver driving conditions. The ESC module continuously compares each dampers command state with the state of their feedback circuits to ensure they agree.

Conditions for Running the DTC

    • Battery voltage is between 9-16 volts.
    • Ignition ON for 30 seconds.

Conditions for Setting the DTC

The damper coil or the circuits to the coil are shorted to ground, shorted to voltage, or open for 3 consecutive ignition ON cycles.

Action Taken When the DTC Sets

    • The driver information center (DIC) displays the SERVICE SUSPENSION SYSTEM message.
    • If the DTC symptom 01 is stored, the electronic suspension control (ESC) system is disabled.
    • If the DTC symptom 02 or 04 is stored, the suspect damper is disabled.

Conditions for Clearing the DTC

    • A current DTC will clear on the next consecutive malfunction-free ignition cycle.
    • A history DTC will clear after 50 consecutive malfunction-free ignition cycles or the DTC can be cleared with the scan tool.

Diagnostic Aids

    • Before proceeding with the diagnostics, ensure the electrical harness connector at the suspect damper is fully engaged by pushing the harness connector toward the damper. If an audible click is heard, or substantial engagement travel is noted, ensure the remaining damper connectors are fully engaged as well.
    • When the scan tool is used to clear the DTC, the ESCM ignition cycle counter is disabled for the remainder of the ignition cycle. This allows the DTC to set upon initial malfunction detection. Once the ignition is cycled, the counter resets to 3.
    • The scan tool can be used to command the suspect damper ON and OFF while actuating the suspension and noticing an increase and decrease in damping control.

Reference Information

Schematic Reference

Electronic Suspension Control Schematics

Connector End View Reference

    •  Electronic Suspension Control Connector End Views
    •  Electronic Suspension Control Component Views

Description and Operation

Electronic Suspension Control Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Ignition ON, command the damper actuator ON and OFF while jouncing the vehicle in the front and rear. Suspension should change stiffness when commanded between the ON and OFF state.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the applicable suspension damper.
  2. Test for less than 1.0 ohm of resistance between the low reference circuit terminal B and ground.
  3. If greater than 1.0 ohm, test the low reference circuit for an open/high resistance.
  4. Ignition OFF, perform this setup step in the following order:
  5. 3.1. Connect a test lamp betweeen the control circuit terminal A and the low reference circuit terminal B.
    3.2. Ignition ON, with a scan tool, clear all ESC module DTCs.
  6. Command the applicable damper ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  7. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the ESC module.
    If the test lamp is always OFF, test for a short to ground or an open/high resistance on the control circuit. If the circuit tests normal, replace the ESC module.
  8. If all circuits test normal, test or replace the applicable suspension damper.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the applicable suspension damper.
  2. Test for less than 2 ohms of resistance between the control circuit terminal and the low reference circuit terminal of the applicable suspension damper.
  3. If not within the specified range, replace the applicable suspension damper.

Repair Instructions

    •  Shock Absorber Replacement
    •  Control Module References for ESC replacement, setup, and programming

Repair Verification

  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced. This would include the Suspension Position Calibration procedure.
  3. Clear the DTCs.
  4. Use the scan tool Diagnostic Counter Reset output control function to bypass the 3 consecutive ignition cycle requirement for setting a DTC. This will ensure that if a DTC was to be reset during the repair verification process, it will be displayed on the scan tool.
  5. Turn OFF the ignition for 60 seconds.
  6. Turn ON the ignition.
  7. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure