Rear Parking Sensors Issue Or Limitation?

[IronFist]

I have the OEM rear parking sensors and it appears everytime when it rains or if the weather is really cold the sensors go off even when there's nothing behind the car.

When the weather does warm up (ie: midday) the sensors work fine.

Just wondering if anyone experiences this or is it just the way they are or is it a 'standard' Lexus thing??

This is my first car with rear parking sensors. My other car doesn't have sensors so I can't really compare.

[MzLeXuS]

I have the OEM rear parking sensors and it appears everytime when it rains or if the weather is really cold the sensors go off even when there's nothing behind the car.

When the weather does warm up (ie: midday) the sensors work fine.

Just wondering if anyone experiences this or is it just the way they are or is it a 'standard' Lexus thing??

This is my first car with rear parking sensors. My other car doesn't have sensors so I can't really compare.

I also got rear parking sensors but i dont experience that problem.... I wouldnt be able to tell ya what the problem is, i have no clue bout cars...lol sowi :P

[Niick]

I dont have any sensors, just the reverse camera. I remember being in my mates commodore when it was pouring down and he couldn't see crap, but the sensors were fine. You should just give Lexus a quick call im sure they will give you some sort of assistance.

[IronFist]

I dont have any sensors, just the reverse camera. I remember being in my mates commodore when it was pouring down and he couldn't see crap, but the sensors were fine. You should just give Lexus a quick call im sure they will give you some sort of assistance.

Yeah, sounds like it's not common and only unique to my car. I'll have to get Lexus to look during it's next service.

[Sapphire Cam]

Jomster - sounds like an issue unique to your car. I have authentic sensors installed by the dealer and have worked perfectly all the time in any conditions. Im assuming your sensors are Lexus genuine parts. The problem you describe are typical of the cheaper over-the-counter DIY sensor kits.

So yep, get your dealer to sort it all out.

[Naz]

Hi Guys,

I have the same problem on mine. I had mine fitted by the dealer too. I usually find it happens on weather extreme days. If I go around and tap the sensors at the back it all settles down

[IronFist]

Hi Guys,

I have the same problem on mine. I had mine fitted by the dealer too. I usually find it happens on weather extreme days. If I go around and tap the sensors at the back it all settles down

Hey Naz, for my car I usually find if I tap the last sensor on the right of the bumper (The one on the curve of the bumper) it settles down.

I don't know if it was a fluke or whether the problem lies with that one sensor.

I even used fine compressed air to clean out in between the grooves but evently it occasionally comes back to haunt me during bad weather. I'm not sure if it's temeperature related or water related?

My sensors are the the genuine factory item I was told before I bought the car. They look exactly the same as the ones from you get straight on a factory fitted car. However my first service isn't due for a long time but I'm sure going to bring it up then.

Apart from that, the car has been going great.

[Naz]

Hey Jomster!

Thanks for the reply, I will check my right sensor the next time it happens. My service is not due for a few months yet, I think my car is on 8K so I think I might get there in about 6 months so I will keep you posted to how I go :>

[IronFist]

Digging up an old thread...Still an issue unfortunately 3 months after the service.

As part of the car first service - The rear sensors were looked at by the dealer but no problem could be identified.

And it has been working fine ever since, however lately with the Sydney downpour and combination of cold weather - The rear sensors are playing up again.

It seems a little chill factor and the sensors just do a continuous beep. The problem is I can't replicate the issue on demand. If it can't be replicate Lexus don't think there is a problem.

I've read the manual that came with the car on the sensors and they are well within the operating temperature...

I've cleaned the groves of the sensors with compressed air...still no luck. It just works whenever they feel like it.

What are your thoughts, anyone experience this?

[Sapphire Cam]

Gee - I have Lexus fitted sensors, and they have been perfect., so Im surprised at this blog entry. I do know that in absolutely torrential rain (not that we've seen anything like tat in Melbourne for past 10 years), anything to do with sonar/radar can go 'skew-whiff'. (like radar cruise control whic for safety reasons can shut down in extreme rain).

But Ive never had any problem in any conditions (hot, cold, frost, fog, rain, dust).

[uad]

try putting the sensor in the freezer for a day, take it out and re-install it. Not sure if that would work, but i heard some friend did it and it worked.......just make sure the temp in the freezer is not too low to damage the sensor

[bobsmith]

Wouldnt any benefit form putting them in the freezer be short term ie when they warm up they will become faulty again?

[IronFist]

Still no luck, I definitely know it's climate related. The Sydney chill factor these days have made it a common thing...

Been reading some of the comments of other forums, people in the US tend to install a kill switch as ice and snow freeze over the sensors causing them to emit a continuous beep. However this was mainly for the front sensors where each time they hit the brakes it would just beep. I thought this application may also work for the rears also. Just food for thought.

Just wondering, does anyone know where the 'control box' is? even the buzzer that beeps (I can trace the wire)

I had someone put the car in reverse while I walk around the rear to see where the beeper is coming from. I think it's in behind the rear garnish or the boot lid itself...Can anyone confirm this?

Behind the rear bumper there's no access from underneath, I'm hoping it's just a bad connection somewhere where I can just fix myself.

If I can't replicate the problem, Lexus says that there's nothing wrong and I look stupid. This is driving me nuts.

[steven250]

I have the OEM owners manual and installation guide in front of me and the operating temp says minus 15 to 70.

I have attached the layout of the components - hope it helps.

[IronFist]

Thanks for that steven250, I'll see first if it's a connection issues (which I'm hoping it is) if I can resolve it myself.

The pamphlet I got when I bought the car new also says operating temperature -15 to 70 deg which is false if mine can't even work at 12-15 degrees.

[Naz]

Hey Jom,

Did you get anywhere with this? I seem to be having the same problem now :)

[ilv1004s]

hm.. thats wierd

mines a factory fitted (sports) sensors

not a single problem

def chase it up with the dealers

[IronFist]

Hey Jom,

Did you get anywhere with this? I seem to be having the same problem now :)

Hey Naz,

I did get it fix in the end under warranty. It was two defective sensors they had to replace.

The '09 Sports Luxury loan car I had rubber grommets around the centre cylinder thing to prevent crud getting into the sensor which the dealer fitted options didn't.

They are a factory part but I think they are a Toyota part because they look exactly the same as current model Toyotas.

It was frustrating for me because I couldn't replicate the issue all the time and when I finally did they replaced it.

The way I troubleshooted was (Make sure no obstacles behind the car) :

1) Ignition in accessories mode (Engine off)

2) Have the gear in reverse

3) Disconnect the wire plugs to each sensor one at a time.

4) When it shuts up you've found the defective one

Get it look under warranty if you still got some or you can buy them separately which I can't recall what the price was.

Lexus also confirmed the ones I found.

[Naz]

Thanks Jom,

How do you disconnect each sensor at a time? Do you have to find some sort of hub or ECU that the sensors are connected to? Or did you pull the bumper out? I pulled the spare wheel lid and had a look around and I could not see the unit that controls all the sensors so I am not sure where to look, I have not pulled out all the carpets in the boot yet.

Any tips are appreciated :)

Also any pictures of this rubber thing that fits on the sensors?

I got the delaer to fit it before I got the car but I am not sure if it's covered by the car warranty?

[IronFist]

I did it a few months ago so my memory is a bit sketchy.

I took out the bottom on the bumper by unbolting underneath the rear just enough so I can get my hands behind each sensor. There's a bolt underneath each wheel arch as well as the middle clips. Follow the contour of the bottom of the bumper and you'll see.

The US guys has told me you could also unhook one or both mufflers just enough to get your hands through - But I haven't tried this methond.

Each sensor unclips from the main harness. You'll see when you can get behind the bumper.

The main ECU is on the left hand side wall of the trunk and the buzzer is on the parcel shelf. But you don't need to go this far. Do the easy stuff first by checking the sensors themselves cos this you gotta removal 3/4 of your trunk trim possible to get to.

Did you get your car under a dealer or factory warranty?

In my case, I knew what was wrong and I did the hard investigation stage myself cos I wanted it fixed.

All they did was change the part.

I actually do have a photo of the rubber grommet. I just need to find it first.

Good luck. Let us know if you need a hand or if your in Sydney come to one of our upcoming meets.

[Iggy]

just to put in my 2 cents: I have just noticed the same issue last night and early this morning, but they work fine in during the day? I am thinking it may have something to do with condensation which gets moisture to settle into the connection and causes the sensor to go off. Maybe the connectors are a little loose and do not seal well. I'd love to put it appart and have a look, but then I thought stuff it, let Lexus worry about it.