2020 Tundra integrated brake controller

Your truck is under warranty, take it in. Have you tried the trailer on another truck?

 

Thats the same harness I used on my 18 Tacoma.

 

No I haven't tried the trailer on another truck but I did try to adjust the brake shoes on the teiker even more with very little results. I know it's under warranty but this issue has been a know problem for several years.

 

I thought plug and play was dead after 2017 or 18? Haven't had an issue with the integrated one so far myself.

 

Just because you read something on a forum doesn't mean it applies to you. My 2020 brakes my trailer very well and weights 5.4K. I only run the gain around 6 to prevent lock up. Trying the trailer on another truck will verify if it's a trailer problem or a Tundra problem. I still believe you most likely have a trailer problem. Your trailer is new and trailer brakes take a long time for them to seat in properly. Trailer brakes are pretty low quality and if you have ever set a pair of new shoes in a trailer brake drum they dont fully mate with each other. After a fair amount of use they will start to work into each other and will start to work properly.

 

I've read similar here... but wanted to be prepared for issues so I will have the P3 all ready to go if needed.

I will give the factory controller a try first though before I go making more unneeded work for myself.

 

This is very true.
I've had many new trailers over the years and they always take a little while for the shoes to seat and start working properly.
Eventually once they burn-in... you should be able to lock all 4 tires up behind you pretty easily.

 

Plug n play harness dosent work on my 19. Havent looked at any other tundras to see if that is the case on 20s though.

etrailer does have a work around, but does require running some wires into the engine bay.

 

Maybe you have the wrong harness? I had a 2019 4.6L that I installed an aftermarket controller on. The factory harness is on the pass side behind the side kick panel. I used the tekonsha harness to connect to it and it worked just fine.

 

On my 2019 it is... and I'm thinking it was the same on the 2018. Pretty sure it was 2017 and earlier that could use the PnP harness from Tekonsha.

 

Any luck in diagnosing with the info I provided?

 

I just now saw your files. Thank you, I’ll take a look at them. The links don’t appear to work.

I took the trailer out for a drive for about 30 miles trying different braking techniques. Since I’ve added brakes on the second axle and rewired the connections from wire nuts to soldered joints I was hoping for better results. I still cannot lock up the brakes even at the gain set to 10.
What I did notice is if I hit the truck brakes hard at slower speeds it does cause the trailer to dive just a bit which indicates to me that they are capable of working. I’m curious if the controller is meant to be less aggressive in it’s stopping unless you really stomp on the brakes. I’ve replaced the connector on the trailer side. I haven’t had a chance to try it yet. I might connect it to the truck and do more voltage checks at the trailer junction box.
Im thinking I will end up buying a Curt Spectrum brake controller. I like that solution better than the P3. To me, the way the P3 juts out from the dash is ugly. If I had to I’d mount it under the dash where it would set back.
With the IBC removed a blank plate could be manufactured to fit in place of it. I think the knob would fit nicely there.
Unfortunately the Curt Spectrum with the adaptor cable is expensive at around 235 dollars shipped.

I don't have a lot of faith the connector replacement will help.

I’ve been kicking around an idea of using something like a Buck Converter. It’s a dc-dc converter. So when the controller only sources 11 volts the converter can be adjusted to output 12 volts or what ever you adjust it to. The only issue I can see is I don’t think they are linear. That, and if it fails at some point will it fail with no voltage or full voltage? Either way could cause sever pucker factor.

 

All of the IBC replacement makes me wonder if when you replace it does it kill the VSC? Do they work together? That’s actually helpful.

 

Here’s the latest finding from my IBC and trailer brake issues. I replaced the connector on the trailer to be sure that wasn’t causing the voltage drop. It wasn’t. Today I removed the IBC from the dash to check supply and output voltages. Everything looks good. Engine running I’m showing over 13 volts into the controller. With the trailer connected and slider at full deflection the output at the controller is 12+ volts.
At the rear bumper socket with a lightbulb connected to the - and the brake terminal I’m reading 12+ volts. At the trailer junction box where the cable from the trailer connects to the truck I’m reading 11.4 volts. I’m losing 1 volt at that junction box. I cut the brake wire in the junction box to take it out of circuit from the trailer and connected the lightbulb and 12+ volts. I checked the resistance of the bulb and it reads 1.2 ohms. I check the resistance of the trailer brake wiring and it is 0.9 ohms.
Using a clip lead I tied the trailer back into the brake wiring circuit and 11.4 volts.

From what I’ve been reading the trailer HAS to have at least 12 volts in order for the brakes to work properly. So the difference of 0.3 ohms appears to be pulling to much current for the trailer controller to source thus dropping the voltage to 11.4 volts. At .9 ohms it’s pulling around 13.3 amps according to ohms law. At 1.2 ohms (light bulb) it should be pulling 10 amps.
Actual readings are the trailer pulls 12.3 amps with the engine running. That controller should be able to handle upwards of 18 amps.
So, not sure what is going on yet.

I just finished rewiring the ground side for the second set of brakes I installed. Now at the connector I show 1.4 ohms and 13.3 amps of current draw. Still only 11.6 volts. That’s the highest value I’ve seen yet.

I’m thinking a new controller is appropriate at least for testing. I’m up in the air over the Curt Spectrum or the Redarc controller. I like that mounting solution better than the box solution.

 

Very detailed and informative. I'm thinking about going the way of the bluetooth brake controller.

 

Please post your findings. I’d like to know how well they work.
I ended up buying the Curt Spectrum. About the time I did that the Toyota service manager calls me and wants me to stop by one more time to have a look at my IBC. He wants to make sure the correct firmware is loaded in the ECU. I just had it in their shop for an oil change and an update to the ECU per the Toyota TSB. Interestingly, it wasn’t documented on the service receipt.
So I haven’t installed it yet. I’ll wait to see if he finds anything. He also told me there is really nothing else he can do and stressed the I should call the Toyota Customer Support number and file a case with them. He said they actually do try to help when customers have issues.

We will see what happens.

 

The dealer couldn’t find any issues with the IBC. He compared the output against a 2018 Tundra and found the voltages were the same. He also checked the firmware rev in the ECU and said it was at the correct rev. So all in all nothing has been resolved. At this point I purchased a Curt Spectrum controller. I’m hoping that will take care of the problem. I might have it installed by tomorrow and hopefully tested.
I used a 2” x 1/8” piece of aluminum plate to cover the hole where the IBC was installed and and painted it with black tool dip from a rattle can. I like this solution better than the P3 solution.

 

I've been following these threads for a while now, has anyone put a p3 on a 2019-2020 Tundra yet? I want to make the change, but want to verify it will not throw a code or at least can be corrected. The dealer couldn't say one or the other.

 

Ive got my P3 on standby... but sofar the factory controller has been working just as good.
Very smooth and will easily lock up the trailer brakes if needed.

 

Are you having issues with an IBC on a new Tundra? I know they had issues around 2016 but I thought those had been resolved on the newer ones.

 

yes, I have a 2019 and brake controller is super soft even at 10. I tow a 7500lb travel trailer. I took it to the dealer they said everything was fine. The first representative tried to tell me the brake controller doesn't work with the brakes, it only works manually the slide, they were a joke.

Tested the trailer brakes with a friends non-tundra truck and they worked great. I do a lot of camping up north in Az and I already had one instance of my truck front brakes overheating because the trailer brakes weren't stopping enough coming down a slow grade.

 

Does your trailer have led brake/turn lights? Read through this thread amd maybe try one of the resistors to see if it fixes it.

https://www.tundras.com/threads/201...t-connected-warning.25341/page-5#post-1213972

Might not help as you arent getting the disconnect error, but might be worth a try. Someone in another thread said the resistor gave them more braking force.

 

Yes LED brake lights and signal. Thanks, I’ll check it out.

 

Finally got to tow with my 2021 with the integrated brake controller:
- It defaulted to "Electric 5000+" mode. No idea how to change that, apparently no one else knows either. (If you do... please post some pics)
- When using the manual slider I could not get my trailer brakes to lock up. But then again, I used to have a Tekonsha P3 and it wouldn't lock up either! (Airstream trailer has "auto adjusting" brakes, nothing I can do about it.)
- Set the gain to 7.0, and braking actually ends up being much stronger now compared to the slider. I don't think the unit gives as much gain on the slider as it does via the pedal.
- Eventually dialed it down to about 5.0, this gives the smoothest braking and feels much like a normal stop

I guess I'm happy with the Tundra IBC, it works for me. The P3 had some more bells & whistles but I don't think it was any better or worse. The Tundra controller seems to be "one size fits all" and I understand that some may not like it. In that case, get an aftermarket solution.

Edit:
Here's a video that shows where to find the electric/hydraulic setting
https://www.youtube.com/watch?v=tAs-6EDzrAE&feature=emb_logo

 

I don't think older models like 2016 have the fancy menus.

 

Same here. I bought a new double axle trailer and it took a few trips for the shoes to seat. When empty, I had to have the gain up at 6-7. Now that they are seating, 2-3.

 

Debating what to do here. Got my 2020 last August, towed my 16-foot E-Pro travel trailer 3 times until I got the "trailer disconnected" error in October. The truck has never been able to connect to the trailer since then. Lights still come on but that seems to be it. Trailer connects fine to other vehicles.

Do I even have Toyota look at it and try to fix it? The integration is awesome when it works but do I really want it going out in the middle of a big mountain trip this summer? Million Dollar Highway is no joke.

I love @Don308 's aluminum filler plate solution if I go another direction. I would prefer to get a Redarc Tow Pro Elite like I had in my 4Runner and that looks great.

 

Toyota IBC Failure:

Driving back from Utah to Ca, I had issues with my IBC. Intermittently at first then to complete failure. Babying it over the Wasatch Mountains in the snow and Donner Pass in the Sierra with no trailer brakes.

I qualified the wiring of my new trailer (less than a year old) and found no issues. I further qualified it with another truck and confirmed that the issues lies within the tow vehicle - 2020 1794 with less than 40k on the clock (bought new).

Wiring, fuses, connectors at the 7-pin all check out. Lights un-affected.

The experience with Toyota on the matter has been slightly discouraging. As a former ASE Master tech — at a Toyota dealership 25 years ago…I wonder where they get these kids today…They couldn’t even understand the problem I was trying to explain to them…

Rather than financing a Research Project with Toyota, I am considering following the group think and dropping in a P3 & Harness in my 2020 Tundra… So my question for the group is; Has anyone successfully deployed the P3 in a 2020 Tundra ? The reason I ask is that the manufacturers website does not show that they are compatible with the 2020 Tundra….everything else, but not the Tundra. Is there rhyme to the reason or is this just an inadvertent omission?

BTW: Toyota - if you’re following this post, this known issue has put lives in danger…Please take this seriously or loose a 30 year 6x repeat customer..

 

Well I can't blame you if you drop Toyota. I also worked for Toyota as a tech and my family drives nothing but Toyota but after my extremely poor experience with Toyota customer service with my new Tundra I've since dropped them.