DTC C0575, C0580, C0585, or C0590. Buick Lucerne 2006

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2006 🢒 Lucerne 🢒 Vehicle Control Systems 🢒 Computer/Integrating Systems 🢒 DTC C0575, C0580, C0585, or C0590

DTC Descriptors

DTC C0575: Left Front Actuator Circuit

DTC C0580: Right Front Actuator Circuit

DTC C0585: Left Rear Actuator Circuit

DTC C0590: Right Rear Actuator Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description .

DTC Symptom	DTC Symptom Descriptor
01	Short To Battery
02	Short To Ground
04	Open Circuit

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

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 ESCM continuously compares each dampers command state with the state of their feedback circuits to ensure they agree.

Conditions for Running the DTC

The ignition is 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

•	A DTC is stored in memory.

•	The driver information center (DIC) displays the SERVICE SUSPENSION SYS message.

•	If DTC symptom 01 is stored the Electronic Suspension Control (ESC) System is disabled.

•	If 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.

•	Using a scan tool clears the DTC.

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

Suspension Controls Schematics

Connector End View Reference

Suspension Controls Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Verification

With the scan tool installed, drive the vehicle and monitor the damper actuators response to rough road, or abrupt steering maneuver driving conditions.

Circuit/System Testing

Note: It is recommended that Component Testing is performed before Circuit Testing when diagnosing damper actuators.

With the ignition OFF, disconnect the ESCM connector.
With the ignition ON, measure for 0 volts between the damper control circuit or the low reference circuit and ground at the ESCM connector.

⇒	If over 0 volts, repair the short to voltage in the damper control circuit or the low reference circuit.

With the ignition OFF, measure for infinite ohms of resistance between the damper control circuit or the low reference circuit and ground at the ESCM connector.

⇒	If less than infinite ohms, repair the short to ground in the damper control circuit or the low reference circuit.

Measure for 0.5-2 ohms of resistance between the damper control circuit and low reference circuit at the ESCM connector with the damper actuator connected.

⇒	If greater than 0.5-2 ohms, check for an open/high resistance in the circuit or faulty damper actuator.

⇒	If less than 0.5-2 ohms, check for a short between the circuits or faulty damper actuator.

If all circuits test normal, replace the ESCM.

Component Testing

Disconnect the suspect damper actuator harness connector, with the ignition OFF, measure for 0.5-2 ohms from the male terminal in the center of the damper rod to the damper rod.

⇒	If value is not in range, replace the damper.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Shock Absorber Replacement

•	Control Module References for ESCM replacement, setup, and programming