S025

CODE S025 RR DAMPER SOLENOID VALVE SHORT TO VOLTAGE












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 low-side feedback low when the solenoid is off or during a PWM low state. It also expects to see the high-side low and low-side high during a PWM high state.

FAULT CONDITIONS:
If the RSS control module sees the high-side feedback low and the low-side feedback low for three consecutive samples during an off period and high- side feedback high and low-side feedback low for three consecutive samples during the 5 to 15 mS portion ofthe on period, a code is set.

If the RSS control module sees the high-side feedback low and the low-side feedback high during the off period for three consecutive samples (samples taken at five second intervals), a code is set.

If the RSS control module sees the high-side feedback low and the low-side feedback low for three consecutive 1 mS samples during a hold PWM low state, a code is set.

ACTION TAKEN:
The RSS control module continues to drive the affected 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 of the solenoid 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 valve 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 short to voltage 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 module monitors these feedback lines through all possible states (ON, OFF, PWM HIGH STATE, and PWM LOW STATE).

Since a short to voltage 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 solenoid is closed or non-energized.

NOTES ON FAULT TREE:
[1] Refer to notes on intermittents.
[2] 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.