2020 TRD PRO PCS issues after car wash

Yesterday I had to stop and get gas at Shell and the tank was a little low. It took a little over 19 gallons. (the gas thing is prevalent). I got a free car wash from one of the touchless ones and I always turn off my PCS due to the chance of the truck braking automatically on me and there was a warning that went out from Toyota on this. It did slip my mind and by the time I thought of it the water already hit the front of the truck, nothing happened with the PCS yet.

I drive home full tank and car washed (short trip less than 10 minutes) and I got to turn into my subdivision and the PCS Off warning indicator was on. I get it home and shut it off and turn it back on and the light is still on. So I fire up techstream and the code that was thrown was the steering wheel angle sensor but there was no PCS alarm like other PCS functions. That was the only light that was on and the only code. The live reading system said the light was on but it was no longer reading the fault but I wasn't sure how long it took the light to turn off as there were no active codes now.

I reset it and the light went off. I started it off and took a short ride around the block, no issues no light. Today I took the truck about for a longer ride and still no light so a good sign I guess but when I pulled into the garage, pressed the button to shut the truck off, and the truck made this loud gurgling noise and it sounded like it came from the back and I googled it and said something about a really full tank could cause this but I didn't top the tank off yesterday when it clicked I stopped. Now yesterday it was 60 degrees and last night it dropped to 30 and we are at 46 degrees right now. It kind of freaked me out because I was looking around for a leak, no leak but it was probably less than 15 seconds but I certainly never heard this before. The vehicle has only 7000 miles on it.

Everything that happened seemed to coincide with the car wash yesterday and fill up. Obviously, I reset the code so going to Toyota and having it looked at is pointless until it happens again, especially if techstream isn't showing a fault after it threw it, but just wondering if anyone else experienced anything like this. One other tidbit I put in 87 in the truck for the first time as the Plus which I usually put in they were out of and I know the truck is rated for regular 87 and I use Shell gasoline. I'm kind of wishing I didn't get the vehicle washed yesterday. LOL.

Sean

 

Never seen that warning from Toyota and I wash mine weekly pressure wash full blast to the front and many times with the Hood open to clean the Radiator and everything around it.

I am adding this: "PCS Light Flashes or illuminates"
Could indicate malfunction of the PCS or that the system is temporary unavailable due to the vehicle being extremely Hot/Cold or due to dirt / snow or ice around a front sensor.

I have had mine go off due to mud and snow/ ice... I just cleaned dried it off went on my way.

 

First page it mentions when PCS might activate and it mentions car wash. The dealership even mentioned it to me when I bought the vehicle to turn it off as the vehicle might slam on the brakes by itself and make the alert noises. They said every time they put one of them through their automated car wash at the dealership they have to disable PCS in all 2019+ Toyotas that have the TSS.

https://www.toyota.com/content/ebrochure/CFA_TSS_precautions.pdf

I agree I have read some other feeds about tacomas and tundras doing this also and at first, I thought it was just the front sensor got hit with heavy pressure and caused it to happen. So I went ahead and dried off the sensor in front, made sure it was dry around it and the light still stayed on. That is when I decided to check the codes to see which one and I expected it to be the front radar sensor and not the angle wheel sensor that is located in the steering column and part of the PCS system to my surprise. I did wait about a hour to see if the code would clear on it's own, drove around for bit, lots of stops and starts just to see if it would reset and it didn't, live data from techstream shows the code did pop but was no longer in any fault state, so I wondered why it didn't go away if there was no issue. That is when I got it home and decided to reset it.

I called a mechanic friend of mine after I posted today and he said he would look into more tomorrow once he gets to work about the PCS code but he said the loud gurgle / growl that sounded like from the back of the truck was possibly some pressure or some trapped air being released from the fuel tank but told me to keep an eye on it and see if it happens again tomorrow. If it does he want me to bring it by the shop so he can listen to it and see what it might be. He did say in all these newer vehicle that if anything is wrong even the slightest thing they will throw codes which mine hasn't since yesterday.

Sean

 

I’ve got a 2018, so what’s PCS?

 

It's all the safety features they started adding in 2019 on to the 4runners and other vehicles that didn't have it. It stands for the Pre-Collision System.

 

Thanks, I think I’ve asked before on another thread but forgot. Appreciate it.

 

Those started being used in 4Rs in 2020, not 2019. None of that on my OR.

 

Apparently some dealerships said they did.
https://www.lexingtontoyota.com/blog/what-safety-systems-are-available-on-the-2019-toyota-4runner/
https://www.seminoletoyota.com/toyota-reviews/2019-4runner.htm

 

We know that all dealerships are always right 100% of the time.

I've not seen one 2019 4R with the TSS sensor on the grille. None of the aftermarket grilles for up to 2019 have a TSS sensor cutout.

https://pressroom.toyota.com/the-ad...ains-new-safety-and-multimedia-tech-for-2020/

https://www.heritagetoyotacars.com/blog/toyota-4runner-gains-new-safety-features-for-2020/

 

The way I read the PDF you linked is that PCS (braking) could activate in a car wash. Not that it would throw an error code afterwards because of a car wash. Think in terms of all the stuff that is coming at the vehicle at a regular carwash…big rotating brushes coming at the vehicle left, right, from the top…poor thing probably thinks it’s getting attacked from every direction lol. To have the vehicle respond by applying brakes frantically while it’s getting dragged along in the car wash could be a problem, so I think that is why they mention it. But if you are in a stationary touch-less wash, I cant see why it’s necessary to turn off the PCS system, or why the dealer would say to do that.

The PDF describes two modes of “failure”, or errors: one is “may not detect” (failing to activate when it should), and the other is “may operate when collision not likely” (applying emergency braking when it should not). While I love the “may operate” PR positivity of how the marketing dept describes the second error mode, that it’s this error that is most concerning to me …because it overrides the driver’s input. This error has the potential to be the actual cause of an accident (imagine emergency braking in traffic, for no good reason). Nobody on the self-driving, yay safety systems! camp likes to talk about this stuff, but at least toyota is being more honest than tesla regarding how their safety systems can be the cause of an accident.

Another thing that can be gleaned from this list of potential errors, is that PCS is not using just the front radar to make its decisions. They describe a system that relies on input from the radar for detection of “things”, a camera with pre-programmed visual templates of common dangers (standing people vs crouched people, drawings of standing people, speed of walking…for example), steering angle, braking, and probably yaw sensors too. It’s all a very complex interplay of data , and it seems to rely on templates and patterns of data to make it’s decisions.

The PDF doesnt mention how the VSC (stability control) can punt you off the road for no good reason as well (failing sensors), but maybe because everyone has pretty much accepted VCS by now.

You (OP) have a steering angle sensor code. I cant see how that is linked to the car wash. However, Im surprised you dont have a VCS error light. Probably should get that steering angle code resolved. Emergency braking when not necessary is bad, but the VCS trying to straighten you out by applying braking to the left brake discs at 70mph, when you are already going straight, is arguably scarier.

The gurgling sound might be linked to the car wash, but only if you left the gas cap off lol (yeesh, that would be bad). Or if you have clogged or disconnected evap lines somewhere.

 

2019 is when the driver assist camera on the windshield started. The radar in the grill wasn’t available yet.

 

Nah all of that safety stuff did not start until 2020. I have a 19 Pro and it has nothing of the sort on it. Just how I like it.

 

Yeh I was surprised there was no VCS light or any other lights. I was actually still in motion when the first stream hit the car wasn't even expecting it, maybe it was a prewash but I was in motion, I just cleared the height sign with the front of the car and I still had maybe 25 feet to get to the place where I had to stop. The wheel did bump against the track and the gas cap was closed and locked. As I said the angle wheel sensor when I got home said it was no longer in fault on techstream on the live view and the code was thrown was just in memory and that was the only code on the entire system being thrown.

 

I am glad I only do my own hand wash. I will have to put a note in for dealer to not wash when I have service done.

 

Your right, it was 2020 model years that started selling in 2019 that I’m thinking of.

 

And make sure Not to Drive when it is Raining....

 

Mine shuts off the TSS all the time when the radar panel gets covered with snow.
I live in New England. It snows here. Cant do much about it, .............
unless Toyota wants to add a defroster to the radar panel in the grille?

 

mine does too! That flat radar panel makes it a common occurance that it gets covered in snow. That’s fine. I dont mind if the system decides to tap out and tell me Im on my own. It’s even polite enough to tell me on the display that PCS is unavailable.

However, I would mind if it tried to kill me by activating when it shouldnt. Failing to save me, and trying to kill me, are two completely different things lol.

That said, I think the OP had an actual error code in the system, which is different. Even though he had just gone to a car wash, the steering angle code he got doesnt seem to be related to the to the car wash, at least on the surface.