TSS Pre Collision System

New to this site with a quick question: I've got a 2023 4X4 Off Road Tacoma with a factory installed TRD lift. I have noticed that the "pre-collision" system with the cruise control "active" works great. However, when it is not activated and the PCS system is configured for maximum detection, it only detects at about 4 feet from the vehicle in front. I have had it in for service twice to check on this but I am told everything is operating as normal. I never intend to rely on the PCS for purposely traveling too close to another vehicle but just checking to see what the consensus is on how accurate this should be at maximum detection.
Thanks!

 

What are your expectations from the pre-collision system? How are you testing it to determine it only works 4 feet out?

 

Actually, the Toyota Service Manager test drove the vehicle after the second time I brought up the issue and could not get it to activate at any "Safe" distance that he thought it should work at. He agreed that there was a problem and it was brought in to service where it was "supposedly" checked, found with no issues and re-calibrated for good measure.. I have carefully drove up on a few vehicles extremely carefully to notice the alarm and "BRAKE" indications (ensuring the conditions were met to activate). Distance was 4 feet or less. I have never pressed to test beyond that to see if the automatic PCS system activates the braking system like when the cruise control is activated. The cruise control activates at a very acceptible distance.

 

Please tell me you are doing this with another vehicle you own somewhere that isn’t busy and not with strangers… As far as I’m aware there is not way to “test” the system short of driving recklessly fast and placing the vehicle in a position of imminent collision without pcs intervention.

What are these conditions and where did you find them detailed?

My guess is the truck can tell you aren’t actually in danger and is only activating PCS at 4 foot because that’s the distance it thinks it needs to be able to safely stop. This seems like a really silly game to be playing. Safety systems either work or they don’t. You don’t test your airbags do you?
You never said what your expectations of the PCS are. Have you read the description of its functionality in the manual? It seems like your expectations may not match its function.
If it is dealership calibrated, that’s as good as it gets.
I’m sorry I can’t be any help, hopefully someone else will have more insight for you.

Edit: I don’t mean to come off as antagonistic! I just haven’t seen anyone asking or worried about this before

 

You are 100% correct. Certainly not looking to put anyone in danger. Let me backup and say for the record that this whole thing got started when I noticed a message in the info center that stated "PreCollision system malfunction. See dealership". I cleared this thinking it might be residual from when the lift was installed and the new grill and sensor relocation but took it in to service just to be sure. Like I said before, the service manager took it for a test drive and said it was not working as it should. In morning traffic, a teenager did a wreckless lane change and cut in extremely close to the front end. He said it absolutley should have activated but didn't. I was just trying to get a feel from other owners on how sensitive this warning system should be. I agree that it woks, but I 'm not so sure that it is calibrated as it should be. Lets be honest -- Today's service departments will not recognize a problem unless a fault code is present and that is especially true when a vehicle is under warranty. It is not presently throwing any codes.
With that said, I appreciate the feedback and will probably call it good!

 

I apologize for the tone in my previous messages. Rereading them now they seem unnecessarily combative and sort of condescending.
Welcome to the forum! Share a pic! Everybody loves to look at tacomas around here

That’s totally fair! I was bucking against the service managers input, but not taking into consideration multiple mods affecting the sensor or that there could have been an unintentional close call.
What kind of lift did you get and how high? Your new grill is the pro with the TOYOTA lettering and a rectangular garnish that has a cross hatch pattern on it in the 6 o’clock position?
I’ve read that some people have had issues with aftermarket sensor garnishes. I’ve also read about people putting a washer or two on the bottom mounting screw of the sensor to sort of angle it down more, trying to offset the lift height and the change in sensor position if that makes sense.

 

While I don't care about that feature, I've wondered (but not researched) if the sensitivity is speed related like @musicisevil alluded to. Mine hasn't ever gone off while parking and I've never had it go off while driving. Not driving on crazy busy roads or highways yet, I've had enough space for the speed I'm driving to not have to hit the brakes real hard to prevent hitting the vehicle in front of me. Which also makes me lean towards speed/distance related. Doesn't explain why yours hasn't gone off sooner than 4 feet if you're traveling more than 20mph. heh, Maybe it is within specs and you've just been miraculously driving 2mph slower than what it calculates to alert you based on your fast braking reflexes.

Good point.

On the flip side I wish I could turn off that feature on my wife's 2023 CX-50. On the minimum setting it alarms 30 feet out and even a couple of times when a snow plow has gone by in the opposite direction. Scary to have the brakes hit hard and the steering pull away from the "perceived collision" on a snowy road.

 

My PCS has only gone off once and it was at high speed with an idiot in front of me. Worked from a pretty good distance (5+ car lengths) about half a second before I did. Stayed on longer than needed though. It's an emergency feature to reduce accident speeds not a daily driving feature. If you're testing at low speed I'm not surprised by lower distance.

 

No offense taken on your reply musicisevil -no apology necessary! The truck had the TRD lift already installed with custom 285/70/17 tires and wheels on the showroom floor. So,it already has the TRD Pro Grill and OEM sensor along with the standard vehicle warranty covering this if it becomes a problem and starts logging faults.

I appreciate everyone's feedback! (On the other hand, it could be much worse where the sensor goes off all the time which would actually be more annoying and dangerous)!

 

It activates somewhere above 32 MPH. I think it is also detecting (and considering) the speed of the object in front of you too, so testing essentially requires you to deliberately nearly crash in to something.
For instance; while I don't drive that way, I could tailgate someone at speed and it won't go off, but if I was quickly approaching a vehicle or object going much slower, it will activate. It is essentially factoring the difference of speed, which is what is dangerous.

 

From my personal experience, the PCS has to have a few conditions to light up the brake. I'm not sure what those conditions are though. You can tell through it's dynamic cruise how well it "sees" objects in front, because it tells you. But just seeing the object isn't enough. There has to be a relative speed differential between you and the object up front, and I'm guessing that the conditions of that delta are expressed as a percent and not an absolute. There also has to be little input from you the driver to make it think that you're not paying attention. I've noticed that if I'm changing my speed before it alerts, it never will alert.

All of that is a guess, but just from observation over the years on what it alerted on and what it didn't, I think it needs multiple conditions to initiate an alert.

 

exactly! I am sure Toyota holds the algorithm in a guarded vault as well.
It is kind of strange though, to the OP's point. How the hell is the dealer to ever verify proper function? It seems they would at least have a scan tool or something to force a system check while stopped.