2018-2021 Tundra adding 5th (Spare) Tire to Instrument Cluster Display

Thanks to @azTony we just reprogrammed his TPMS ecu to add the spare tire and show 5 tires on the display.

I posted a thread long ago where I discovered I could display a 5th tire pressure on the cluster screen by sending it specially formatted CAN messages. See more here: https://www.tundras.com/threads/2018-tpms-codes-finally-cracked.105009/

The Tundra TPMS ecus has the ability to store sensor IDs for one main set of tires, up to 5 total including the spare. From the factory the ECU is set for only 4 tires however, leaving the spare out. Unfortunately, Techstream has no option to change the TPMS ecu from 4 to 5 tires. I spent the last several weeks testing my benchtop TPMS ecu and now have a way to reprogram it to 5 tires. We just tested it on Tonys 2018 Tundra with success.



If any other members are interested I can do this for you also for a small fee.

A few things you will need.
1) A 5th TPMS sensor installed in your spare tire. (Can be added in afterward)
2) The ID of the 5th Sensor (Can be added in afterward)
3) Any ELM327 OBD adapter (Tony and I used the Veepeak via bluetooth)
4) The free windows software "Real Dash" from the Microsoft app store. Its free and has a great interface to communicate with the ECUs of the truck.
5) A Windows laptop that can connect to the ELM327 device and run Google Chrome Remote Desktop.
6) Toyota Techstream software, IF you want to register your new ID and set it to the spare location at the same time. I assume any tire shop can do this for you also, or the Autel units people use.

Tony shared his screen with me remotely and I used the software on his laptop to communicate with his truck via ELM327 to reprogram the ECU to 5 tires. Afterward he used Techstream to enter the 5th sensor ID and set it to the Spare location at the same time. I assume the display will show the spare as --- until you set the new ID and location to Spare with Techstream.

The TPMS ecu will stay set to 5 tires forever unless someone reprograms it back to 4 or the ecu is removed and replaced. The new sensor can be added anytime afterward, the display will not show the actual number until the new sensor is added and registered.

Fee is $50 and I will set aside an agreed upon window of 30 mins to work with you. This is less than what I charge for a half hour of my time as an engineer, and less than what the stealer ship will charge to tell you that they can not do it. Also I have years of time invested into working with and understanding communication with these ECUS. I cant just do it for free, my time is worth something.
If it cant be done remotely, removing the ECU and shipping it is an option, but you will probably spend most of that $50 in shipping fees back and forth to me.

The remote option with an ELM327 OBD device is easier for you and I both.

I am really excited to see this finally working. I personally think it is really cool.

 

I just want to give a HUGE shout out to Da Man @Jeff_5_7 for using a 2018 setup for his testing. I have been looking all over trying to figure out how to change that one number in Techstream and that was the magic. Time well spent my friend and sorry about the slow Toughbook, it came through in the end!

 

Well I got excited for a cool DIY to try, then I saw you’re only offering it as a service… good on ya, but I’d suggest moving this to the marketplace if that’s the case.

 

Good point… didn’t think about that.

DIY lead to Pandora’s box for me but I think I owe you a favor for some 2018 Tundra CAN logs. Feel free to shoot me a message.

 

Haha you don’t owe me anything. It was cool to help out on that end.

This isn’t something that I have to have, but it’s pretty cool and I’m curious.

 

Following this. Definitely cool and useful. I may have to add this to my to do list. Good job @Jeff_5_7

 

So, this is NOT in the EEPROM in the instrument cluster, correct?

 

Correct, it is however in the EEPROM of the TPMS ecu, I know that because the ecu never forgets the setting when power is completely removed. It just tells the ecu to recognize 5 tires instead of the factory 4.

When you tell it to work with 5 tires it then relays data for the 5 to the cluster instead of sending data for only 4. This gives you 5 readings on screen instead of 4.

I assume Toyota didn’t want to pay to put a 5th sensor in every truck at the factory so they just told the Ecu to only work with 4

 

Got it
You helped me get set up flashing the instrument cluster for ODO when we were digging into the parking sonar (much appreciated again). Just wanted to be sure this wasn’t something I could do through that.

 

No completely different ECU, but you got me thinking maybe either in cluster or TPMS Ecu a setting exist to disable the warning light completely. I know alot of 2007-2017 guys just want the little orange light gone for good.

 

That orange light has never bothered me, it does it's job when required and only then

 

Does anyone have a recommendation on which brand TPMS sensor to use? I tried searching spark parts and came up empty on a stock unit.

 

I would just hit the local tire shop and get one that's compatible

 

The 20/21 needs the OEM sensors as does not like aftermarket. Let me find the part number.

 

42607-0C091

 

Fantastic, thanks @Tundra234

 

I should add, I think some people have mention they had a sensor in the spare from Toyota factory.

I am not sure if this is true or not or how to check if one was installed at the factory however. Maybe by looking in Techstream.

 

I have never seen or heard of anyone that had one in the factory spare. If you look in Techstream and can see the 5th TPMS then it would show on the dash from what we went through. There was no way for me to register 5 ID's only 4 because that is the tire count stored in Techstream and from I have found there is no way to update that one field from a 4 to a 5. Once that was changed to a 5 the 5th tire shows up but without a registered TPMS sensor there is no way to get a reading. All 5 TPMS's need to be registered to receive a reading of all 5.

You can go to a place like Discount Tire and ask them to do it for you. I doubt they would if you walked in and never been there as a customer before because they did not want to to it for me. I was pretty pressing on the guy and he went and got a manager. We talked through it and he said it would only take a minute to scan the spare. We walked out and the kid seen my tire in the bed strapped down and said that would have to come out of the bed so he can scan it. I was standing on the tailgate and he was in front of me and he laid the scanner down. I had it scanned in a couple secs. I took a picture of the screen for the ID and handed him the scanner. No words were said as we parted. Some peoples kids...

 

This is exactly what I’ve been waiting for!

I will be getting my ducks in a row with the parts and pieces necessary on my end, and get in line for a remote tuning session.

Thanks for figuring this out!

 

Wow, this is slick. Well done sir.

 

Jeff,

What OBDII cable do you guys use? I also poke around in techstream under TPMS and found an option to switch from 4 tires to 5 tires but unable to get it to switch. It kept on saying lost connection. I can switch TPMS IDs around but unable to register new ones or switch from 4 to 5 tires.

Thank you

 

We did Tony’s wireless with a Bluetooth ELM device. The cable is not near as important as the communication protocol. I checked several different times in Techstream under Tundras and never saw an option to switch from 4 to 5 tires. Where did you find it?

Maybe Techstream is sending data on a protocol not supported by your truck?

 

It should be listed under ID Registration/Tire Position Write. I attached pictures of what I found on techstream. Are you using the latest version?

 

In all my testing that function is for setting the IDs for all 4 or 5 tires, but that’s the second step in the process. The first is the function to set the TPMS ecu from 4 to 5 tires which I never found in Techstream.

The Tundra ECUs I tested would only hold one main set of up to 5 tires sensors.

Does your home page of the TPMS ecu list IDs for 5 or just 4?

What is the number on the second row next to Main Tire? If it’s 4 it will only accept 4 ids, if it’s 5 yours has already been switched to 5 ids but if that’s the case you should have seen it on the instrument cluster, assuming you have a 2018+

No really big incentive to add a 5th tire to a 2017 or older unless you have a headunit or 3rd party way to monitor the data.

 

Mine is 4 below main. At the registered 5th ID code : I have all 0s. Under 5th ID pressure is N/A. While Techstream is running, I notice that both 5th ID code and 5th ID pressure are "flashing" as if the truck is looking for the 5th signal.

My truck is 2021.

I tried to switch my wife's 4Runner 5 TPMS sensors around and it failed. So I am leaning toward "bad" cable. Since the 4Runner has the 5th wheel function.

Edit:

Bad cable confirmed. I can now add "spare" wheel and have it displayed on the dash via TechStream.

 

Does this make 5 tire rotations seamless?

 

You can still have more than 4 TPMS programmed to your truck, at least on 2018+. I've got all 5 of mine programmed, without this mod (it'll get done eventually...), and the computer picks them up fine after the next drive. I can't remember if I had to push the TPMS reset button or if it picked them all up automatically after I drove a bit.

 

odd I can’t get my truck to pick up the 5 sensor and it’s caused my TPMS light to be on.

 

All 5 TPMS were registered by the tire shop? You can try some of the troubleshooting mentioned here: https://www.tundras.com/threads/anyone-have-luck-resetting-tpms-after-tire-rotation.111802/

 

The tireshop probably activated the 5 wheels option on your truck because I drove around with 5 sensors for a while but only 4 show up until I activated the 5 wheels option via TechStream.