The LF damper actuator is driven by the CVRSS module via a method known as Pulse-Width Modulation (PWM). Battery voltage is modulated (switched on and off) at a high frequency (2.0 kHz), thus, controlling the amount of current delivered to the actuator. By controlling the amount of current to the actuator, the CVRSS module can then control the damping force in the damper. 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 (with no battery voltage, and thus no current, provided to the attached actuator) is one that provides a minimum damping force.
The DTC is set when the CVRSS module measures a feedback voltage between two preset thresholds during two consecutive OFF-state damper diagnostic test procedures.
The DTC is set when the CVRSS module performs a test procedure on each damper actuator approximately every 16 seconds. During this test procedure the damper actuator is briefly energized (ON-state test) and de-energized (OFF-state test). If, twice consecutively, the feedback voltage during the OFF-state test is inside the open circuit range, the corresponding DTC is set.
The DTC turns HISTORY when the CVRSS module no longer senses an open circuit condition on either of the two actuator lines.
• | The LF damper actuator will be disabled by commanding 0 percent PWM duty cycle. The LF corner of the vehicle will be soft. |
• | The SERVICE RIDE CONTROL message will be displayed. |
• | Use the scan tool. |
• | Use the On-Board diagnostic CLEAR RSS CODES feature. |
Important:
• Do not backprobe the sensors, actuators, or any sealed connectors. • When all the diagnostics and repairs are complete, clear the DTCs
and verify the operation.
The number(s) below refer to the step number(s) on the diagnostic table.
This step checks for an open circuit condition in the actuator or the actuator pigtail.
This step checks for an open circuit condition in CKT 1448.
This step checks for an open circuit condition in CKT 1005.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Was the Road Sensing Suspension Diagnostic System Check performed? | -- | Go to Step 2 | |
2 |
Is the resistance value displayed within the specified range? | 9.5-15.5 ohms | Go to Step 3 | Go to Step 7 |
3 |
Is the resistance equal to or less than the specified value? | 5 ohms | Go to Step 4 | Go to Step 9 |
4 | Measure the resistance between connector C1, terminal D12, and damper connector terminal B (harness side) with a J 39200 DMM. Is the resistance equal to or less than the specified value? | 5 ohms | Go to Step 6 | Go to Step 5 |
5 | Repair the open circuit condition in CKT 1005. Is the repair complete? | -- | -- | |
6 |
Is the DTC C1711 or C1712 set? | -- | Go to Step 8 | |
7 | Replace the LF damper. Refer to Strut Assembly Replacement . Is the replacement complete? | -- | -- | |
8 |
Important: The control module must be calibrated. Is the CVRSS control module calibrated? | -- | -- | |
9 | Repair the open circuit condition in CKT 1448. Is the repair complete? | -- | -- |