My 2014 ES 350 recently started showing a Check Park Sonar warning. The rear sensors work (show up when backing up and there is an obstacle behind) but not the front ones. If I switch it on when there is nothing in front of the car for a while, no warnings but when driving as soon as I near a car in front the check park sonar warning starts again (and doesn't go away then even if there is nothing in front of the car for a while).

Has anyone experienced this or know what might be causing it?

 

So the issue is that the front ones, once they are activated, don't go away after the obstacle is removed from the front of the car?

 

Yes, if there is no obstacle in front at startup or when switched on then I see the "P" active like normal but if there is an obstacle when it is switched on or if later an obstacle is present, it shows the check park sonar message. My guess is that maybe 1 of the 4 sensors isn't sending a signal (which it doesn't know till there is an obstacle in front and it gets inconsistent information from the sensors and shows the error message) but I could be wrong which is why I wanted to see if anyone else has experienced anything similar.

 

We leave our parking aid on all the time, so turning it on/off may cause it to calibrate or run a self check. One of the sensors may have caught some road debris, or a stick, leave, etc is stuck on it. Might be loose connection, or a bad wire/short in it.