Fault Detection:
The air suspension ECU performs fault detection and plausibility checks. Fault detection is limited to faults that the
ECU can directly measure, as follows:
Sensor hardware faults
Valve hardware faults
Sensor and actuator supply faults
Bus failures
ECU hardware errors.
Plausibility checks are checks on signal behaviour are as follows:
Average height does not change correctly
Height changes too slowly
Suspension moves in the wrong direction.
Reservoir pressure
Does not increase when reservoir filling requested
Does not decrease when reservoir used to lift vehicle
Does not decrease when reservoir is vented
Pressure varies too much when inactive.
Compressor temperature
Increases when compressor inactive
Does not increase when compressor active.
'Energy' used to change height of corner
Too much 'energy' used – height change takes too long or long term filtered height does not reach target.
Sensor activity
Signal floating
Inconsistent signal characteristics – signal on one side of axle is varying but other side remains static
Constant articulation when moving.