2020 TRD Pro PCS Pre Collision System Malfunction

I hopped on here because recently on my 2020 4 Runner, the "Pre Collison System Malfunction take to dealer" warning came on. Trying to gain a better understanding of the issue. There have been some pretty informative posts on here so far.

A couple weeks ago I had the front windshield replaced, it had a crack in it. No collision or anything just needed replaced. The front camera behind the windshield was recalibrated without issue at Safelite auto glass.

This week we replaced the original factory Nitto Terra Grapplers (265/70R17) for a set of Nokian Outpost AT's (also 265/70R17). They also suggested an alignment which we did.

When I got the call that the tire & alignment was completed they had asked if that warning light was on previously? It was not.

So I think this scenario between a new windshield, tires (although same size), and an alignment has created the perfect storm to take the ADAS out of calibration just enough to cause an issue.

The guys at Safelite & my Tire shop have all been extremely helpful and this is not a bash or negative on them. They double checked their work and been very professional. I have an appointment at the dealer in a couple weeks to get it checked out and hopefully resolved. And hopefully not alot more money...

I figured I would share as this seems to be an issue thats not too uncommon. Maybe this process can help someone else make some informed decisions going forward with their 2020 or newer 4 Runners with TSS, ADAS, and hopefully not as big of PITA (see what I did there?

 

Had my windshield replaced, swapped out my suspension and went with larger tires (285/70/17’s) all in the same week. Didn’t have an issue with the PCS.

Honestly I can’t recall anyone else posting a similiar issue to yours on the forum. Best bet is the dealer or if it’s out of calibration a competent shop to recalibrate it. I don’t deem safelite as competent.

 

Definitely seems like it "Shouldn't" be an issue.

 

This is on the dash at all times. Can't use cruise control either till thats fixed.

 

Hope it is simple as some dirt got into the camera behind the windshield when they install the windshield. I don't know what is the process to cover it when scrape the old silicon or any thing and make the surface clean before applying new windshield.

 

Taking a wild guess here, but maybe zero point calibration needs to be reset after the alignment for some reason. Can the shop that did the tires pull codes?

I was inclined to blame safelite, but it did go a couple of weeks with no problems…

 

That would be great if it were that simple! I wouldn't complain.

 

Good question. They do have diagnostic software and went through double checking their work & codes. I dont believe our Tire shop has the equipment or software to calibrate it though.

They've been great and actually very inquisitive as to why it started doing this while in their shop. We're going to learn together on this one. Its kindof an anomaly.

Logically the windshield OR the alignment would make sense since the tires are same size. Between all 3 variables (Windshield, Tires, Alignment). Strange though how it went a couple weeks after a windshield install without issue. ‍

 

Blame Safelite. My fiancé had her windshield (2017 IS with all the same tech) replaced this last week because of a rock that cracked it. She took it to Safelite and they re-calibrated and all seemed fine. Two days later (no extra work, no alignment, nothing), this same error popped up on her dash. We have been out of town, so haven’t had an opportunity to get it looked at, but I would NOT rule out Safelite’s fault simply because of elapsed time.

 

Appreciate your feedback guys!

 

During normal operation you can use "normal" cruise control by holding the cruise control on button for a few seconds, which will turn off adaptive cruise control. Maybe even with the PCS error "normal" cruise control will still work.

 

That is tremendously helpful! Thank you for that bit of info

 

The same thing is happening to me. I have it a body shop they are trying to see if they can fix what Toyota can't. I only have 6,000 miles on my vehicle and the dealerships had it for 6 days trying to figure it out and they could not and told me to take it to a body shop. I'm so aggravated over this.

 

More common than most of us would like. There is literally another post within the past 5 minutes, similar situation (no windshield replacement or tires though). These TSS systems are glitchy imo.

 

Drumroll.....

Had my dealership appointment today and they were able to diagnose my issue.

The windshield installed by Safelite will need to be replaced with a Toyota Windshield.

The forward camera bracket attached to the aftermarket windshield is larger than spec. So the forward facing camera (behind the rear view mirror) is sitting in there loose and bouncing around.

I believe they said that if it reads out of spec so many times in a row it will set off that Pre Collison System Malfunction code untill its recalibrated.

So now starts the process of filing an insurance claim to have the aftermarket Safelite Glass swapped for a Toyota piece of Glass simply because of that bracket that holds the Camera.

Hindsight I should have gone to the dealer for the Glass. The deductible is the same either way and I'm going on close to a month of inoperable cruise control. I'll keep this thread updated, I hope this helps someone else!

 

Another Drumroll...

Some going back n forth between appointments with the Dealership, Safelite, my insurance company. The issue has been resolved and have approximately 1200 miles without a repeat issue. Interesting though we ended up not replacing the Safelite Windshield.

The vehicle had several fault codes. Brake Systems, ABS, Telematics, ECU, Crawl Control.

The Solution: Codes cleared, recalibrated the zero point calibration along with recalibrating the crawl control.

To my understanding my dealership has not seen this issue or combination of issues with any new 4 Runners to date. All previously have been due to aftermarket Windshield install. Also, it is undetermined why this issue started in the first place or a direct cause.

Such a strange deal! But its fixed with no lights on the dash and cruise control fully operational! I'm a little skeptical of the camera being "loose" in the front windshield. So I do plan to adjust my insurance for OEM replacement in the future as I will most likely need it replaced within a year again anyways. Lots of highway & mountain driving!

Takeaways:
-The local Dealer has been nothing but fair & reasonable to work with. Ultimately they fixed my vehicle when others could not.
-Might be a good idea to have OEM insurance & have the dealer do my tires next time.
-All parties involved have been professional & reasonable.

Hope this helps another vehicle owner in the future.

 

On my Prius, those problems are usually fixed with washing the car (seriously). I also worry the computer is malfunctioning.

The PCS is mostly driven by that radar plate on the front grill.

Also, check your radar cruise function.

My last flare-up of PCS issues were caused by a dying battery...

 

Occasionally while driving in the rain or snow the cruise knocks out and it prompts me to check the radar sensor. Same, just needs wiped off occasionally if its too dirty.

 

Maybe a coating of a silicone wax or polish, or a treatment sort of like Rain-X might be appropriate in the case of a dirty sensor causing a malfunction.

Since the 1980s, I have used either Teflon or a silicone based wax for my windshield. It makes a world of difference and, in Southern California, it lasts so long time.

I have used traditional Meguiars or Turtle Wax for my radar sensor in washings past, I am now rethinking that... prompted by this thread.

 

Not a bad idea. That would help

 

Just changed the oil on my 4Runner. Now I get the PCS malfunction. I had the entire car jacked up on stands and was working the 4WD system and lockers. Needless to say after I did that the PCS won’t clear. I disconnected the battery for 30+ minutes while changing the oil on my wife’s van. I just drove ~20 miles and it did not clear. It is clear and nothing blocking it. Anyone have ideas on resetting the PCS warning? I can’t use cruise control now. Even if I disabled PCS. If anyone has ideas please let me know. Otherwise I might have to take it to the dumb mechanics.

 

No exact answer, maybe it's one of those things where you've got to run the car five different starts, 20 minutes each trip or 200 miles, etc.

I know that I've had to do that for a smog check on another brand of car. I needed to cycle the car something like a few starts and short trips before the fact that I cleared the codes also disappeared from the system...

Good luck, I'm sure Toyota would want an arm and a leg to diagnose that. How dare you DIY!

 

The only solution I was able to come up with was a trip to the dealer to get it recalibrated and the codes cleared. That was after I went on a couple road trips and maybe 4000-5000 miles too.

 

How much did the dealer charge you?

The recalibration for my cross traffic radars ran over $500.

 

Mine is under warranty and if that is the case I want all this fancy crap pulled out ASAP. This is dumb. Toyota software engineers thinking about how to make a profit. No need for recalibrating as it was working just fine for over a year until I pulled this dumb stunt to excercise the 4wd after I changed the front diff fluid.

 

In T-SB-0026-20 Rev1 March 18, 2020, it says if they deactivate the PCS, it's toast.

I'd avoid mentioning any work you've been doing and just say "it suddenly happened." They'll probably know you've disconnected the power, but I wouldn't volunteer it up front.

Hopefully, you have cool service advisors. In Southern California, my local dealerships are absolute asses, they have even denied warranty work on certified used cars and denied replacements on Toyota parts that were damaged in shipping to me. I drive an hour north and get great service.

 

I want to say it was only $140. Honestly it was all the back n forth between my tire shop, glass repair company, insurance, and the dealership. There were so many factors in the mix I would have gladly just paid that to begin with. Every party involved was good to work with but it took over a month to get ironed out. Except my insurance... they still haven't called me back.

 

Well my father-in-law had a scanner tool. We scanned it and nothing came up. But he had an ABS button and it had an error there for the ABS system. Long story short don’t run your car on jackstands. It messes them up. Anyways I was able to clear the error and no errors are showing up. Cruise control is functioning as designed now. I will probably forget to follow-up here if the error doesn’t come back. But if it does it will require further inspection. I drove down the street and no issues at all. As soon as I cleared the error the PCS alert went off.

 

Hey, so stupid question. Do 4runners have the auto brake feature if the "BRAKE BRAKE" warning flashes on screen? I'm asking because mine didn't auto brake and I slammed on the brakes. Rear ended someone. I've driven a lot of different Toyotas and they all had the brakes auto engage. No warning lights about the sensor or anything.

 

This is a good question, it would be silly just to beep and sail into the vehicle ahead since the car clearly has the ability to apply the brakes via automation (ATRACS). On the other hand, with such a rudimentary system they might not want to risk getting rear-ended.

Check this thread to reset the PCS yourself via techstream on a 2020+.