So I am stumped. I had a passenger side sensor that indicated bad (fault with no obstruction). I swapped the passenger with the driver corners and the problem moved to the driver side. I replaced the two driver side corners with new ones (Toyota) and I cannot get the fault on the driver side to go away. I disconnected one of the EFI fuses for 30 seconds hoping to reset the ECM after a mechanic friend thought there may be a fault that will not clear on its own. This worked for a minute but the obstruction indicator shows a problem on the driver side front once again.

I have two questions:
1) Do I need to reset the sonar system via a scan tool or something else?
2) If there is no reset needed does anyone know how to test the sensors to see what might be wrong? How about the harness?

I hope I do not need to take it into the dealership

Thanks!

 

Sorry to ask again however I cannot find an answer to this one. Does the ECM or control module need to be reset?

 

Don't know about a reset. Don't think it saves any data over time, therefore, there is no need for it to be reset. But I don't know for sure.

Try cleaning the sensors and the area where the sensor goes in very well. Small dirt particles might be throwing your system off.

 

This is absolutely the best first option. There is a small grooved ring in each sensor that collects dirt (even though not obvious to the eye). Dirt will send off false positive signal in the sensor.

 

I am getting a fault with new Toyota sensors. Really at a loss. Perhaps its wiring however not exactly sure what to test for.....

 

30 second battery disconnect may not be enough. I'd try several minutes (10) of battery disconnect, not just EFI fuses. Since the false positive started on the right side and moved to the left side when you moved the sensor, if resetting was needed, then both the right and left side should still be pushing false positives?

 

I pulled back the top of the front bumper and I am guessing that there must be a harness issue. All of the sensors are positively seated and only the driver side fails. I better be sitting down when I see how much Lexus wants for this simple connectorized cable. It appears all sensors plug into it. As a FYI my friend who is a certified mechanic read all codes and there were none so we are thinking that an obstruction does not throw codes.