DTC C0577, C0579, C0582, C0584, C0587, C0589, C0592, or C0594 F55
Circuit Description
The strut actuator is controlled by the Electronic Suspension Control (ESC) module with a Pulse-Width Modulation (PWM) signal. Switching the voltage ON and OFF at a high frequency (2.0 kHz), or pulse width modulating, controls the amount of current delivered to the actuator. By controlling the amount of current to the actuator the ESC module controls the damping force in the strut. A higher level of damping force is achieved by providing correspondingly higher current levels, relating to higher percentages of PWM duty cycle. The default damper state, which is no battery voltage, is one that provides a minimum damping force.
The ESC module periodically commands each strut actuator to a preset PWM duty cycle in order to override the normal PWM command. During this preset PWM duty cycle, the ESC module is able to perform a diagnostic test on each strut actuator to determine if a malfunction is present. The preset PWM command can be either an OFF or ON state duty cycle.
DTC C0577, C0582, C0587, or C0592
In order to test for the conditions that set the DTC C0577, C0582, C0587, or C0592 the following must be present:
The ESC module must first command the strut actuator ON. If the voltage detected in the damper control circuit during the ON state is less than a preset value, the DTC will be set immediately.
DTC C0579, C0584, C0589, or C0594
In order to test for the conditions that set the DTC C0579, C0584, C0589, or C0594 the following must be present:
The ESC module must first command the solenoid ON. If the voltage detected in the damper control circuit during the ON state is between two preset values, the test is repeated. If the ESC module again detects voltage between two preset values, a DTC will be set.
Conditions for Running the DTC
DTC C0577, C0579, C0582, C0584, C0587, C0589, C0592, or C0594
The following conditions must be present to run the DTC:
| • | The ignition is ON. |
| • | The ESC module is in command ON state. |
Conditions for Setting the DTC
DTC C0577, C0582, C0587, or C0592
The following conditions must be present to set the DTC:
| • | The ESC module detects voltage less than a preset value during two consecutive ON state tests. |
| • | The fault is detected during three consecutive ignition cycles, or during the same ignition cycle after clearing the DTC with a scan tool. |
DTC C0579, C0584, C0589, or C0594
The following conditions must be present to set the DTC:
| • | The ESC module detects voltage between two preset values during two consecutive ON state tests. |
| • | 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
DTC C0579, C0584, C0589, or C0594
| • | The SERVICE SUSPENSION SYS message will be displayed. |
| • | ALL the strut actuators will be disabled by commanding 0 percent PWM duty cycle. |
| • | The vehicle ride will be soft. |
DTC C0577, C0582, C0587, or C0592
The following conditions must be present to run the DTC:
| • | The SERVICE SUSPENSION SYS and SPEED LIMITED TO XXX messages will be displayed. |
| • | ALL the strut actuators will be disabled by commanding 0 percent PWM duty cycle. |
| • | The damper relay control switch will be opened and the damper relay de-energized. |
| • | The vehicle speed will be limited. |
| • | The vehicle ride will be soft. |
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 detects the fault during two consecutive diagnostic tests. The DTC will clear if the fault does not return after 50 consecutive ignition cycles. |
Diagnostic Aids
If the DTC is a history DTC, the fault may be intermittent. 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.
-
Tests for short to ground and short to B+ on the control circuit.
-
Tests for continuity from the ESC module on the control circuit and the low reference circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Suspension Controls Schematics | ||||
1 | Did you perform the Electronic Suspension Control (ESC) Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Electronic Suspension Control |
2 |
Does the resistance measure within the specified value? | 0.5-2.0 ohms | Go to Step 3 | Go to Step 7 |
Test the damper control circuit of the actuator for a short to ground and short to battery. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 4 | |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 5 | |
5 | Inspect for poor connections at the actuator. 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 6 |
6 | 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 9 | Go to Step 8 |
7 | Replace the strut/shock absorber. Refer to Strut Assembly Replacement in Front Suspension or Shock Absorber Replacement in Rear Suspension. Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the ESC module. Refer to Electronic Suspension Control Module Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
