Suspension Control - Speed Sensitive Suspension (SSS)

CIRCUIT DESCRIPTION

An actuator fault occurs when the actuator position feedback signal has not achieved and remained at the commanded actuator position within 6 seconds after the actuator has been activated. Actuator faults result in deactivating the faulted actuator. If the actuator fault is present throughout two consecutive ignition cycles, it results in storing error Code 25, and activating the "SERVICE RIDE CONTROL" message. The system will continue to operate all nonfaulted actuators normally.

Recovery of the faulted actuator will occur after a successful one second self diagnostic test which is repeat every 3 minutes until all faults are cleared.

A mismatch of the commanded feedback signal and the actual feedback signal which occurs after the 6 seconds will not be detected as an error. The actuator will not be repositioned until the system commands a new actuator position as a result of new inputs or a 3 minute retest.

TEST CONDITION(S)

The control module will monitor actuator position voltage for correct feedback sequence during an actuator move.

FAILURE CONDITION(S)

A fault is detected if the actuator position feedback sequence is incorrect, or if more than 6.0 seconds is required to complete a move. If actuator position feedback voltage is incorrect for two successive ignition cycles, set code.

ACTION TAKEN

Record actuator position error, turn "ON" "SERVICE RIDE CONTROL" message, disable faulted actuator, retest every 3 minutes.

NOTES ON INTERMITTENTS

In extremely cold weather conditions (-40°), due to the increased viscosity of the strut fluid, the actuator may not reach position within six seconds and set a code.

NOTES ON FAULT TREE

1. Refer to "Notes on Intermittents."

2. The VATS Interrogator (J 34528) set on position 12 or 13 may be used to simulate a 6.6k ohm resistor for output cycling.

3. If dirt or corrosion is found in the top of the strut or connector, clean and recheck before replacing strut.