i have the same issue that popped up 2 days ago.

2020 ORP, 16k miles. I just got off the phone with a couple dealerships cause I need a loaner if my 4runner is going to be in the shop for a few days. Same messages, brake power low, pre-collision malfunction, abs malfunction on the instrument panel. Cruise control malfunction if I try and use it while the messages are up. My messages will come and go, with no real pattern to it. Other than not having traction control or abs, it drives just fine.

Codes I scanned were C1468, C1469, C146A and C146B. Seems to be abs solenoids for each wheel. Hopefully whichever dealership I end up at can resolve this quickly.

This is so weird that I've heard nothing about this issue in two years and now all of a sudden a number of 2020/2021 4Runners on this forum are having the issue within the same week!?!?!? If so many of us on this forum are having the issue, then there must be hundreds more experiencing the same issue not on the forums. It's awfully strange.

We got a Highlander loaner and the service guy said we're looking at 2 weeks in it.

Hi all,

They ended up replacing a major wire harness in my vehicle to resolve the issue. Whatever it was, they had to pull the back seats out to do it, as I drove around without the seats secured while I waited for the part to come in. I'll check my receipt to see if a part number was called out.

I suspect the wire-harness was common between all the sensors acting up, so they decided to replace it. I asked if there was rodent damage (chewing), and they said no, and alluded to all the high speed data travelling in the harness and it is not something that can be repaired, only replaced.

It has been really cold out and I have not seen the issue since the repair, so fingers crossed it is fixed. Good luck!

Jim

See attached image from my receipt... looks like the detected an open circuit and replaced the harness. I didn't realize how much they actually took apart, wow.. Fortunately my truck has been rattle free ever since.

Jim

Attached Images

 

i can't believe i fixed the ABS related issue on my 4runner. it seems like a software glitch on the system. when those error show up, the truck is drivabable except the abs system stopped working and the 4wheel drive system still works for 4h and 2h but not 4L.

while i was driving earlier, i tried pressing the brake with my left foot while i'm pressing the gas to accelerate and suddenly all the error disappeared. i tested the 4 wheel drive system, 4H, 2H, 4L, atrack, traction control and downhill assist started working again. i tested 1 wheel on ice while in 2H and the ABS worked also. if you have these errors, can you try these fix and let me know? there must be something that must have been done with the braking and gas pedal to activate those malfunction. now it's fixed. i wonder if toyota is aware of those issues.

That's a hell of a find. I too was thinking it had to be some sort of electrical glitch given that this issue has popped up with such frequency in the last month or less and only appears to affect those that got the recent winter snowy blasts.

I have little hope that the part our tech ordered is the fix and I hope to God it doesn't lead to the work that jim4runnerny's 4runner needed.

At the start of the thread, Toyota replaced a brake booster and master cylinder. For one 4runner, the master cylinder was the fix. Then jim4runnerny says Toyota replaced a major wiring harness and that fixed it. On our 4runner, they replaced a wheel speed sensor and that didn't fix it. Then they ordered an electronic ABS/brake controller and we're waiting on that. 4r-4ever apparently fixes his 4runner by torque braking it from a roll

I get the sense that Toyota has not a clue about what's happening here. I think the issue is related to a glitch with the Toyota Safety Sense P (TSS-P) system which became available on the 2020 models. That system is heavily integrated into the ABS system, much more so than the previous TSS system.

i know right! i was ready to schedule with toyota to get it looked at. now i'm wondering whether the fix that toyota did was actually the fix. those abs/brake booster probably is not the problem. i just played around with the brakes with my left foot and right foot with the gas pedal and it fixed it. i'm curious now if others who may have the same problem could fix it this way. i would say a software glitch somewhere.

I forwarded this potential two pedal fix to my service advisor and he said he forwarded it to the tech. We'll see. Many techs don't like to be told their job, especially if some guy found something "on the internet". It's understandable. It still worth a shot though.

thank you for forwarding it to your advisor. they might be able to look into this
more and we might all get a software fix to this or whatever recall they need to do.

No word from the service advisor regarding if the tech tried this out. Sounds like they're going to do it the hard way first

I tried last this morning after work and was unsuccessful with making the messages go away. I tried a few times at a few different pressures with no luck.

Ok. good to know. try pressing the gas at around 40miles an hour and hold it there and then press the brake with your left foot. That's was what I did.

2/17 Update

We've been told the ABS module they ordered for our 2020 4Runner likely won't be here for another 1 to 4 weeks. That puts the truck potentially out of service for well over 30 consecutive days, potentially 40+ days. I have little faith that the ABS module will fix the issue either given the multitude of "fixes" listed in this thread. We may be pursuing a lemon law buyback if the module doesn't fix it and the truck has been out 30+ days. Automakers are required under law to keep a sufficient inventory of parts to fix vehicles 10 years or newer from the model year. "Sufficient" is 7 business days or less to get the part. I understand COVID may be creating supply issues, but the law is the law. Not in a million years would I think I'd be considering a lemon buyback on a Toyota, especially the most reliable Toyota in their line up! LOL

Also, they didn't try the brake pedal/gas technique I asked them to try and they won't let us come up and try it either.