Buick Regal: DTC C0575, C0580, C0585, or C0590

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

Left Front Damper Actuator Circuit

DTC C0580

Right Front Damper Actuator Circuit

DTC C0585

Left Rear Damper Actuator Circuit

DTC C0590

Right Rear Damper Actuator Circuit

For symptom byte information, refer to Symptom Byte List.

Diagnostic Fault Information

Circuit/System Description

The suspension control module commands variable levels of current to each shock absorber actuator in response to rough road, braking or abrupt steering maneuver driving conditions. The current variation is performed by pulse width modulation (PWM) of the system voltage. The suspension control module continuously measures the actual current of each actuator. When a deviation between commanded and actual current is detected, a DTC is set.

Conditions for Running the DTC

System voltage is between 9 - 16 V.

Conditions for Setting the DTC

C0575 02, C0580 02, C0585 02, and C0590 02

A short to ground on the control circuit is detected.

C0575 04, C0580 04, C0585 04, and C0590 04

An open circuit on the control circuit is detected.

C0575 0F, C0580 0F, C0585 0F, and C0590 0F

An erratic current on the actuator circuit is detected.

Action Taken When the DTC Sets

• The electronic suspension control is disabled for the duration of the ignition cycle.
• The driver information center displays the SERVICE SUSPENSION SYSTEM message.

Conditions for Clearing the DTC

• A present DTC will clear on the next consecutive malfunction-free ignition cycle.
• A history DTC will clear after 41 consecutive malfunction-free ignition cycles.

Reference Information

Schematic Reference

Electronic Suspension Control Wiring Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEW INDEX

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

Control Module References for scan tool information.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate Q37 Shock Absorber Actuator.

2. Connect a test lamp between the control circuits terminal 1 and terminal 2, ignition ON.

3. Verify the test lamp illuminates.

• If the test lamp does not illuminate

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K19 Suspension Control Module.
2. Test for infinite resistance between the control circuits listed below and ground.
   • Terminal 1
   • Terminal 2
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance.
3. Test for less than 2 Ω in the control circuits listed below end to end.
   • Terminal 1
   • Terminal 2
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • Go to next step: If less than 2 Ω
4. Test for less than 1V between the control circuits listed below and ground.
   • Terminal 1
   • Terminal 2
   • If 1V or greater, repair the short to voltage in the circuit.
   • If less than 1V, replace the K19 Suspension Control Module

• Go to next step: If the test illuminates

Component Testing

Static Test

1. Ignition OFF, disconnect the harness connector at the appropriate Q37 Shock Absorber Actuator.

2. Test for 2 - 4 Ω between the Q37 Shock Absorber Actuator control terminals.

• If not within the specified range, replace the Q37 Shock Absorber Actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Strut Assembly Removal and Installation for front strut replacement
• Shock Absorber Replacement (GNC) Shock Absorber Replacement (GNQ) for rear shock absorber replacement
• Control Module References for suspension control module replacement, programming, and setup

READ NEXT: