if the tilt light is on there should also be an alarm sounding (it may be unplugged)
i would raise the platform using the ground controls, set the maintenance bar and then locate the level/tilt sensor and make sure it is not damaged, wiring to it not damaged, make sure nothing is interfering with it causing it to be tilted over.
Sometimes these tilt sensors will short out and cause the system to malfunction.
One of the tests is to get a mirror and put it under it so you can see the LED's, there should be one lit and when you lean it past the 1.5deg the trigger LED should light and the alarm should sound. If the trigger light is already on then there is something wrong with the sensor and it should be replaced.