In cases where the RSS/FSS give warnings but nothing is within range of the vehicle sensors, or give warnings for 3 seconds then ceases, the occurrence may be due to any of the following reasons:
BLOCKED/CONTAMINATED PROXIMITY SENSOR SURFACE:
Proximity sensor surfaces may be covered with snow, ice, dirt or mud. There is a gap between the sensor membrane and its plastic housing that must remain clear (Figure 1). If this space is contaminated with any foreign material the system may sound a continuous tone or intermittent tone. The sensor surface can be cleaned by a high pressure water spray.
SIDE COVERAGE SENSOR:
There is side/rear coverage that extends approximately 18" (46 cm) perpendicular from the side rear fascia. Side coverage is a desirable feature in a parking situation where the vehicle is involved in a very tight turn with little rearward movement, or where the vehicle is backing parallel to a large, extending obstacle such as a garage wall. If there is no encroachment between any of the outer sensors and an obstacle, then the warning will sound for 3 seconds and cease. If vehicle or the obstacle begin to move closer to each other, then the warning will begin again. Obstacles within 10" (25 cm) of the fascia will always be reported with a continuous tone. This is considered normal operation.
ABNORMAL ROAD SURFACES:
The RSS/FSS may give warnings due to certain road surfaces with surface projections such as rocks, broken pavement, unplowed snow covered roads. This is considered normal operation.
OTHER POSSIBLE CAUSES:
Very wet weather conditions, such as mist, frost or snow may provoke occasional warnings. The system may detect liftgate while open and certain trailer hitches and/or bicycle racks. External ultrasonic noise may be detected (high velocity air, machinery). This is considered normal operation.
