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Annoying collision warning

27354 Views 34 Replies 16 Participants Last post by  adn1962
Hi all,

Maybe winter temperatures and freezing makes the collision warning system grazy...?
After car wash on Friday the warning system turns on when car is running but not moving or just reversing.
The system made the same a few weeks ago when it was freezing but when it got warmer the warning went off.

The red hazard light comes and system makes the beeping sound.

Must go the service and figure out where the sensor is.

Does other members have similar problems?

Cheers Reima


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I believe it's either radar behind the Toyota logo in front or a camera behind a windshield at the top
wipe the frost off ?
When there is ice one the radar, the warning message is that the Pre-collision system is not working.
The message on the picture is from the front IPA sensors - the small round sensors on the bumper. If nothing is blocking them (ice or dirt) one of them may be misaligned and should be checked by the dealership. Sometimes they also may interfere with the rear sensors of the car in front of you - happens to me often behind BMWs.
Many thanks friends for answers.

After cleaning the front sensors the problem still continues and it's a ? why it always turns on while the car is not moving forward.
I'll wait and see if today when it's warmer and maybe go to the dealer. The "minor" problem is that C-HR is a new model also to the service assistants.

Cheers Reima

Maybe a little bit off topic but part of my panel looks as below ( and I was told that it shows that systems are on) . Maybe some of your systems are turned off?
Maybe that could be a reason of collision warning sound.
Sorry for not really visible picture ( inddicators of systems shown: RCTA/BSM/P)
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I got today some information from our Toyota dealer's service, that also the traffic light sensors in buses can cause interference in car's radars.
The service had own experience while driving his own car in rush hour traffic near buses.

I was on a test drive and the dash went blank and just said "BRAKE" and beeped allot. Maybe i was Near traffic lights? Il look later on google lol. No one was anywhere near me.

Ok it was outside a school. No traffic lights and no other vehicles nearby Busses or otherwise. It was around 4 degrees.

Problems still continue when the weather got again freezing and snowing.
Now the PCS-system is out of function...

Got information from our dealer that they won't start any work for fixing this before they have got new information from the factory.
Similar problems are also in Auris models. And this time this problem has nothing to do with buses or other radars.
Let's see if it will be fixed by itself when I take tomorrow my C-HR to warm garage for washing and waxing.



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Happened to me 2 weeks ago. According to my dealer it is due to water entering the radar compartment. They advised in such cases to put the car in a warm garage for a couple of hours so the ice melts and drains.
When I connected the car to my computer it showed multiple errors:
Colorfulness Rectangle Slope Font Line

You can check their code online and see what the problem is.


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JulianoG said:
When I connected the car to my computer it showed multiple errors:
How did you do that? What software do you use and where do you get it from?
I have experienced the same issue. The front sensor continues to beep saying there is a car very close to my bumper, even though there is nothing anywhere near.

Water? Frost? Dirt from the road?

It only happened twice, both times for the final 20 mins of a 1 hours commute. Very annoying.

My local Toyota have no idea and could not replicate the fault. So I'm limbo until they see it for themselves.
david63 said:
How did you do that? What software do you use and where do you get it from?
You need a dedicated cable + Toyota Techstream software which can be purchased from Toyota - Official site
There is an alternative for the cable, called J2534 Mini-VCI which I purchased for my Lexus GS450h. It works fine after some witchcraft with the drivers on x64 Windows.
Been out today, loving my CHR..but...I too keep getting this alarm occasionally..

Does anyone have an update on this fault?
I had it for the first time yesterday.It was a frosty start and it complined the sensor was blocked. But it went away after a few mins when the car/weather warmed up. So I supsect it was a genuine warning not a fault.
Does anyone know where the sensor is ? it possible to wipe it clean?
My warning mentioned the windscreen. Is it in the back of the centre mirror?
My warning did not mention the sensor, it just showed up as the car picture with red warning at the front....It happened when in slow traffic ... I can only guess its front sensor related and not they are around the windscreen which is easy to clean and somewhere by the front badge which is where i too need guidance as to where?...
I was under the impression that it's the sensors on the bumpers. I would guess that the rain/frost plays a part in this. Mine has not done this now for a while now.

Bit silly as this is not new technology and rain/ice is part of driving!!
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