Pre collision warning

[Jonmartin]

I’ve only ever had the car tell me to brake on one occasion. So I’m wondering if it works, according to the centre display it is turned on and shows 3 green bars, supposedly looking further ahead. Anyone out there know if it can be tested without risk to other vehicles, pedestrians or my car ?

i have no intention of relying on it, that would be somewhat silly, just want to know it’s there if needed.

[ian rooke]

hi pull up slowly to a wall when 3 or 4 inches away it should slam the brakes on mine is tested every day as the garage is only 3 inches longer than the car   

[Jonmartin]

I’ll try that, thanks.

[PeteB]

Long grass will do it.

When I got my current Prius, I let a friend drive it to a restaurant where we were in the habit of revering slightly into some long grass.  The rear sensors beep[ed as he approached, and when he got very close braked abruptly.  Although the speed was only 2-3 mph, it gave quite a jolt and my friend was shocked for a moment thinking he'd hit something in my new car!  I was laughing my head off, as it'd done it to me recently when I was alone.   😂

It occasionally lights up when approaching a parked car and leaving the swerve latish to miss opposing traffic without slowing too much.

You see it in action on the NCAP website from when they crash tested the Gen 4 Prius:

http://www.euroncap.com/en/results/toyota/prius/24572

Look for the yellow "Videos" tab.  Pretty impressive

[Jonmartin]

3 hours ago, PeteB said:

Long grass will do it.

When I got my current Prius, I let a friend drive it to a restaurant where we were in the habit of revering slightly into some long grass.  The rear sensors beep[ed as he approached, and when he got very close braked abruptly.  Although the speed was only 2-3 mph, it gave quite a jolt and my friend was shocked for a moment thinking he'd hit something in my new car!  I was laughing my head off, as it'd done it to me recently when I was alone.   😂

It occasionally lights up when approaching a parked car and leaving the swerve latish to miss opposing traffic without slowing too much.

You see it in action on the NCAP website from when they crash tested the Gen 4 Prius:

http://www.euroncap.com/en/results/toyota/prius/24572

Look for the yellow "Videos" tab.  Pretty impressive

Video is impressive. Don’t think I’ll try to find out by driving towards something, though. Certainly mine does not beep or brake when I get close anything. Perhaps an experiment driving towards some like a suspended sheet, might work.

[Jonmartin]

Quick update. I blocked my drive with sheets of cardboard and drove the car at it. Straight through, no warnings or braking, just flat cardboard. The only warning was the sensor saying I was too close to the wall at the side. Off to the dealer on Wednesday, who seems to think it might be a ‘software’ problem. When I collect the car and IF you assure me the PCS is working, I will ask for proof and or a demonstration, don’t think that will be too much to ask.

[PeteB]

Hmm, odd.

On the one hand, I remember seeing a video some time ago (but don't recall where I'm afraid) of a demonstration by Thatcham people like the one in the NCAP video who said the dummy car had realistic general car type features like facsimile number plate & lights, plus some foil in the soft 'body' material as some cars use the camera as well as the radar and sonar to decide when to apply the brakes.  My car certainly brakes if I get close to a metal post in the local shop car park, leaving about a 4 inch gap.

But you're right - I'd want to be reassured the system works.  After all, in my case, one reason I traded a perfectly good 2012 Prius for the latest model 2½ years ago was specifically to get these safety features (and the radar adaptive cruise control, which I really, really, really love!).

[Jonmartin]

11 minutes ago, PeteB said:

Hmm, odd.

On the one hand, I remember seeing a video some time ago (but don't recall where I'm afraid) of a demonstration by Thatcham people like the one in the NCAP video who said the dummy car had realistic general car type features like facsimile number plate & lights, plus some foil in the soft 'body' material as some cars use the camera as well as the radar and sonar to decide when to apply the brakes.  My car certainly brakes if I get close to a metal post in the local shop car park, leaving about a 4 inch gap.

But you're right - I'd want to be reassured the system works.  After all, in my case, one reason I traded a perfectly good 2012 Prius for the latest model 2½ years ago was specifically to get these safety features (and the radar adaptive cruise control, which I really, really, really love!).

When you say your car brakes if you get close to an object. Are you applying the brakes as you approach but the car actually stops for you ?

update. Just tried. Drove the car as if parking, got closer and closer to the ‘wall’. All I got was the proximity alarm beeping and the display showing I was getting closer, but it allowed me to drive through and over the ‘wall’. 

The adaptive cruise works well, does it use the same radar I wonder. 

Anyway hopefully will find out on Wednesday.

 

[PeteB]

A bit of both.  I'm braking gently as the car creeps forward, but when the car thinks I should be stopping it beeps, flashes up "BRAKE" in large letters on the dash (Prius has two 4" screens in the dash, as well as the 8" infotainment screen) and brakes hard to an abrupt stop.

Anyone in the car who didn't know about the system would probably think I'd hit the post!

[Jonmartin]

5 minutes ago, PeteB said:

A bit of both.  I'm braking gently as the car creeps forward, but when the car thinks I should be stopping it beeps, flashes up "BRAKE" in large letters on the dash (Prius has two 4" screens in the dash, as well as the 8" infotainment screen) and brakes hard to an abrupt stop.

Anyone in the car who didn't know about the system would probably think I'd hit the post!

Yeah, mine is the same with the big screen in the middle and a little screen between the instruments. This small screen is the one that is supposed the go red and say brake. It has only done so on two occasions, once when I got close to a car in traffic, fair enough, and the other occasion, for no reason, on a completely empty road. Methinks it’s broke. I’ll update here.

[PeteB]

Yeah.  Mine's never activated without an obvious reason in over 34,000 miles.  Sounds suspicious.

[Heidfirst]

28 minutes ago, PeteB said:

Yeah.  Mine's never activated without an obvious reason in over 34,000 miles.  Sounds suspicious.

mine (in an Avensis) has probably flashed up red about 10 times in the 18 months that I have had the car but has never actually instituted braking.

 Of those ~ 10 times probably on 6 or 7 occasions I understood why it did so (although I already was aware & wasn't concerned) but the other around 3 times there was to me no obvious cause of concern.

[Devon Aygo]

6 hours ago, Jonmartin said:

Quick update. I blocked my drive with sheets of cardboard and drove the car at it. Straight through, no warnings or braking, just flat cardboard. The only warning was the sensor saying I was too close to the wall at the side. Off to the dealer on Wednesday, who seems to think it might be a ‘software’ problem. When I collect the car and IF you assure me the PCS is working, I will ask for proof and or a demonstration, don’t think that will be too much to ask.

There is no "safe or legal" way to confirm on the road that the Pre crash functions are operating, the only way to give any confirmation would be to carry out a calibration of the millimetric radar unit this involves building a "rig" in front of the car this rig has a series of plates with what look like simplified QR codes and reflective squares and triangles these are placed in specific locations and heights in front of the car then using Toyotas diagnostic equipment the radar is "told" where these objects are it then it scans to confirm it see's / detects the objects in the correct positions, if it does then the system is calibrated correctly.

[Jonmartin]

1 hour ago, Devon Aygo said:

There is no "safe or legal" way to confirm on the road that the Pre crash functions are operating, the only way to give any confirmation would be to carry out a calibration of the millimetric radar unit this involves building a "rig" in front of the car this rig has a series of plates with what look like simplified QR codes and reflective squares and triangles these are placed in specific locations and heights in front of the car then using Toyotas diagnostic equipment the radar is "told" where these objects are it then it scans to confirm it see's / detects the objects in the correct positions, if it does then the system is calibrated correctly.

i don’t think asking for some form of proof that the PCS is actually working is too much to ask. It just might save a life sometime. And I would hardly expect the dealer to test it on the road. But what I’ve experienced so far, leads me to believe it’s not working, and if that’s the case then it needs to be fixed. And I need to know, and be shown this is the case, just being told that it’s fixed is not going to be good enough. It is a major selling point for the car and one which was high in my consideration when I bought the car.

[Jonmartin]

On 2/1/2019 at 2:55 PM, PeteB said:

A bit of both.  I'm braking gently as the car creeps forward, but when the car thinks I should be stopping it beeps, flashes up "BRAKE" in large letters on the dash (Prius has two 4" screens in the dash, as well as the 8" infotainment screen) and brakes hard to an abrupt stop.

Anyone in the car who didn't know about the system would probably think I'd hit the post!

Car has been checked and I’m told it’s fine. Got a bit close to cars on the way home and it worked. I did ask about it braking as I parked and they seemed to think that it doesn’t on my model. 

[PeteB]

Difficult to be sure.  I thought the C-HR Excel pretty much mirrored the Gen 4 Prius Excel for key equipment and safe, and as mine's an original spec from when the Gen 4 was launched if anything I'd have expected your car to be even more up-to-date.

Looking at the new car section of the Toyota web site isn't conclusive, and if your manual is anything like mine it will be littered with caveats like "if equipped".  Certainly the 2017 C-HR I drove a couple of years ago seemed to have everything my car has but in a different body (plus it had a nice electronic parking brake with hold feature instead of my foot operated parking brake).