One of my rear parking sensor randomly beeps when nothing is behind me. I've found the most frequent time it beeps is when I'm coming to a stop, but right before I'm completely stopped I start accelerating (gently) it beeps.

I have an obdlink mx+ and TechStream and there's no fault codes. Does anyone know the name of the PID on obdlink or where to look in TechStream to diagnose?

I checked the connections on the rear sensors and they all seem to be secure. When I get time I'll unplug them, clean and maybe add some dielectric grease. I just wanted to see if anyone has experienced the same thing.

 

Are you noticing the behavior while it is raining and/or after a carwash?

Assume you are using Network A



Assume you have "Advanced Parking Guidance..." selected in settings



It's been a while since I did a scan with mine

 

It's not raining or after a car wash when the beeps happen. They're very short, one time beeps and mainly occur when I'm slowing down to stop but just before coming to a complete stop I go from brake to accelerate it beeps.


I just connected to network A and scanned for parking codes and there weren't any.

 

It could be that the sensor is starting to fail but not enough to trigger a code.

https://www.clublexus.com/forums/gx-...stions-17.html

You could swap with the same unit in bumper to see if problem follows. Centers for another center or corner for the opposite corner.

There are 3rd party options but can’t remember offhand if these have been fully successful as not a common failure

OEM
https://www.oemvehicleparts.com/sear...ge_url=&page=1

 

I'm suspecting it might be the rear right sensor. I bought the car used, had a really good service history with Lexus and no accidents reported. It wasn't until a month or so after I noticed that there's a small area in the right rear bumper that looks like it might have been repainted or touched up.

The service manual says the retainer clips for the sensors aren't reusable. If they were and they didn't have adhesive between the sensor and bumper, I'd swap the right rear with the right front (if they're the same part number). When I get time this weekend I'll go with my original plan of unplugging the rear sensors and harness, clean if necessary, put dielectric grease, and reseat the plugs.

I'll also check the resistance between the pins as shown in the service manual.

 

I don’t think you need to remove the retainer to remove the sensor

 

I have been having phantom beeping of my sensors during rain storms for years. I raised this with my current dealer Service Advisor this week seeking a remedy as it just happened last week again during a rain storm. Both on road and in parking lot with nothing in front of me.

Anyone else find a fix? I already changed the sensitivity level with no change in this “intermittent” problem.

I have video from several occasions and a passenger witness. My service advisor didn’t care…they have to duplicate the problem. Mission impossible cause it’s not raining and it’s intermittent.

Could pff/clear bra make this issue worse? Not sure if there are cut outs near sensors. I have a feeling it’s rain and/or wet dirt/oil/muck coming off the road onto the bumper/sensor. But not sure.