Tire pressure light.

[Qjake]

Interesting.... but the only thing that changes to my musing about what might be is that you are not clear which ones of the 5 TMPS sensors within reach are being used to determine the on/off status of the light. Could either be the top 4 slots in the ECU (but then why have 5 available), or there is some signal collision management going on (i.e grab the sensor with the shortest response or strongest signal (in order to determine which one is closer to the sensor).

In case of the latter, you could still have a 5th sensor in the spare that would be functional when mounted as a wheel.

Okki

Do you have a TPM in your spare that is registered in the ECU? Defate it and see what happens.

My 09 Tacoma had 5 from the factory, regardless of which went low the light came on. I can't imagine that Toyota makes different tpms for each vehicle so i'm pretty sure our 4Runners (and every other vehicle made by Toyota) have the same system. The reason spares do not have a TPM in them is most likely a cost cutting measure.

He won't believe you.

:shrug:

 

[philsey]

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:lalala:

:rockthrow:

 

[calcrc]

Ok I lost you guys there, so what you are saying is I should go to the dealer to reset every thing ? Can't I just unplug the battery for 5 minutes o something. When I got my truck it was not with the original tires/wheels and no light came on. It's only after I put on my new wheels that the light started flashing then stayed on.

 

[jrhaze]

Ok I lost you guys there, so what you are saying is I should go to the dealer to reset every thing ? Can't I just unplug the battery for 5 minutes o something. When I got my truck it was not with the original tires/wheels and no light came on. It's only after I put on my new wheels that the light started flashing then stayed on.

Are there TPMS sensors in your new wheels or not?

Sorry if I missed it...

 

[philsey]

Hello all, I don't know if there is ta thread with this but here I go.
Is there a way to disable the tire pressure light on the dashboard ?
I switched wheels and put them at 36 psi and I find the small yellow light annoying. Thank you.

I should have mentionned it. I installed the wheels myself in my driveway about 3 weeks ago.

OK, did you, or didn't you transfer the tpms valves from the old to the new wheels?

ps: Okki and I apologize for the hijack.

Whoops, too slow.

 

[Go JayBee]

Does anyone really use the TPMS to tell if they have a flat tire?
Just sayin'....
Seems like it makes sense to only have 4 sensors...on my 2012 Trail, the spare is on a regular steel rim, so it will never be "rotated" into the other tires anyway.

I know this is not answering the OP's question, sorry...
but this thread has already gone sideways...:tape:

 

[calcrc]

No I did not transfer any valves to the new wheels.

So if I go to the dealer he will charge my like 60$ or I can changes the valves myself ?

 

[K O]

Does anyone really use the TPMS to tell if they have a flat tire?
Just sayin'....
Seems like it makes sense to only have 4 sensors...on my 2012 Trail, the spare is on a regular steel rim, so it will never be "rotated" into the other tires anyway.

I know this is not answering the OP's question, sorry...
but this thread has already gone sideways...:tape:

Have you ever had a flat in your 4Runner? We had a blowout on the freeway (with original stock tires), and the 4Runner handled so beautifully that if it weren't for the dash light I probably would not have noticed as soon as I did. I *thought* I might have had a flat tire and then noticed the dash light on which confirmed it.

Also, it's a good indicator that your tire is leaking and that the current tire pressure is below spec. I doubt hardly anyone actually walks all the way around their vehicle and inspects it before getting in like your state probably has in their DMV handbook as a requirement for operating a motor vehicle. TPMS is great for this vast majority of people who would otherwise never notice a tire that doesn't have enough air to be driven safely or at best is wasting gas.

 

[K O]

No I did not transfer any valves to the new wheels.

So if I go to the dealer he will charge my like 60$ or I can changes the valves myself ?

All tire manufacturers will tell you not to mount tires on your own and to always go to a qualified professional, but if you insist on doing that part, there's no reason you couldn't have also moved to the TPMS sensors.

Edit: How did you balance them?

 

[philsey]

No I did not transfer any valves to the new wheels.

Therein lies your problem.

So if I go to the dealer he will charge my like 60$ or I can changes the valves myself ?

Depends, do you still have the old ones?

 

[harper7]

No I did not transfer any valves to the new wheels.

So if I go to the dealer he will charge my like 60$ or I can changes the valves myself ?

You have to take the tires off the wheels to change the TPMS sensor as it's part of the valve stem.If you can do that ,no problem.If you use the 4 sensors that came off,you won't have to have them reprogrammed.

Nobody has traced the wires to the TPMS ECU to figure which wire to ground or ground to open to shut off the warning light on the 5th Gens...........yet. We have the wiring diagram and if Antman or someother spark chaser guru wanted to do it ,I have faith that they could.The only time mine bugs me is aired down offroad and it would be nice to have a switch to turn it off......hint ,hint ,hint.:eyebrows: I like that it's there when daily driving in case I don't notice a tire going down,and why wouldn't anybody want to know that?

As far as how many readings the 5th Gen TPMS ECU will hold ........Okki is right!That the Techstream software has 5 lines for TPMS sensors .But that's because Techstream is Toyota software for all Toyotas and some can be programmed for 5.

The problem is our ECU will only let you program 4 sensors so philsey is right. I know for a fact ,at least on my 2010 LE that only 4 can be because I too have a TPMS in my spare and had the Discount tire manager try to input the 5th one while I stood over his shoulder and watched.Then I went to the dealer and asked the Service mananger why my 4th Gen would program 5 and not my 5th Gen. He said because low spare tire warnings were one of the most common service calls so they did away with one in the spare AND the ability to even read one there.The beancounters probably told them to say that!!lol

Here's a good thread with Jed on the subject....http://www.toyota-4runner.org/5th-gen-t4rs/68826-rotating-spare-tpms-questions-sr5.html

 

[calcrc]

Well I understand now, I have the old wheels in my basement , but I think the light won't bother me any more since to make it go off I have to take of the tires from the wheels, take off the tpms sensors put them on the other set of wheels and so on. Thank you all guys.

 

[GrantK]

Nobody has traced the wires to the TPMS ECU to figure which wire to ground or ground to open to shut off the warning light on the 5th Gens...........yet. We have the wiring diagram and if Antman or someother spark chaser guru wanted to do it ,I have faith that they could.The only time mine bugs me is aired down offroad and it would be nice to have a switch to turn it off......hint ,hint ,hint.:eyebrows:

I believe that installing a simple on-off switch in the green IND line, pin 5 should do the job but haven't tested it yet.
[EDIT]
The wire might work like the 4LO wire, in that is grounded to indicate active. In that case the switch would need to be double throw. For normal, the signal is handled as normal. For TPMS disable the signal from the ECU is disconnected and in its place either a pull to ground or a pull to high is used. The high voltage could be 1.8V, 3.3V, 5V or 13.8(vehicle's regular 12v).
[\EDIT]

 

[harper7]

Well I understand now, I have the old wheels in my basement , but I think the light won't bother me any more since to make it go off I have to take of the tires from the wheels, take off the tpms sensors put them on the other set of wheels and so on. Thank you all guys.

A strategically placed small square piece of black electrical tape over the warning light does the trick too !:eyebrows:

I believe that installing a simple on-off switch in the green IND line, pin 5 should do the job but haven't tested it yet.
[EDIT]
The wire might work like the 4LO wire, in that is grounded to indicate active. In that case the switch would need to be double throw. For normal, the signal is handled as normal. For TPMS disable the signal from the ECU is disconnected and in its place either a pull to ground or a pull to high is used. The high voltage could be 1.8V, 3.3V, 5V or 13.8(vehicle's regular 12v).
[\EDIT]

I remember seeing the 4th Gen schematic on how to do it but can't find it now as ours should be similar.
Not going to do it unless I know for sure. Could turn out like this if the wrong wire is grounded......

<iframe width="560" height="315" src="http://www.youtube.com/embed/bVUEJurW85k" frameborder="0" allowfullscreen></iframe>

 

[calcrc]

haha I already heard about the electric tape on the check engine light