S022

CODE S022 LR DAMPER SOLENOID VALVE OPEN CIRCUIT









TEST CONDITIONS:
The RSS control module monitors the damper solenoid circuit on both sides of the solenoid valve during the off; on, and PWM portions of the commanded signal. The module expects to see the high-side feedback high and the low-side feedback low when the solenoid is non-energized. It also expects to see the high-side low and the low-side high during the first 1 mS of the on period as well as the high-side low and low-side low during the rest of the on period.

FAULT CONDITIONS:
If the RSS control module sees the high-side feedback low and the low-side feedback low during the off period and also sees the high-side low and the low-side high during the 5 to 15 mS portion of the on period for three consecutive samples (samples taken at five second intervals), a code is set.

ACTION TAKEN:
The RSS control module will continue driving the solenoid. If three consecutive occurrences of the fault occur during the appropriate state, a code is set and the "SERVICE RIDE CONTROL" message is displayed.

DESCRIPTION:
To produce a soft damper setting the damper's high-side is switched to battery voltage to allow the solenoid to move to the open position. After this initial pull-in, the high-side is then pulse width modulated to hold the valve in the open state while reducing current draw. Finally, the high-side is removed from battery voltage to place the solenoid into a closed position which produces a firm damper setting. The damper's soft and firm settings toggle based on various road conditions in order to provide optimal ride and handling.

Solenoid open circuit errors are detected by a high-side and a low-side feedback signal connected to the damper drive and damper return line, respectively. The RSS control module monitors these feedback lines through all possible states (ON, OFF, PWM high, and PWM low). Since an open circuit is not destructive to the circuitry in the module, an error condition is detected but the solenoid continues to be driven based upon road inputs. The default mode for the damper solenoid is closed or non-energized.

NOTES ON FAULT TREE:
[1] Refer to notes on intermittents.
[2] A short to voltage in circuit 1114 or a short to ground in circuit 1115 may damage the windings in the solenoid and create an open.
[3] Refer to clearing codes.

IMPORTANT:
^ DO NOT BACKPROBE SENSORS, DAMPERS, OR ELC / RSS CONNECTORS.
^ WHEN ALL DIAGNOSIS AND REPAIRS ARE COMPLETE, CLEAR CODES AND VERIFY OPERATION.