lepoch

Hi, TPMS light was on. It was the spare...added more air. Then checked the other tires, one was low too and added air. Now TPMS light stays off no matter what position the TPMS switch is in. Any ideas? Doesn't make too much sense to me. The light used to come on when switch was in the 'wrong' position.

2005 GX470 66k miles

mann777

There are many possibilities to that Light being continuously "ON".
1. The battery of the sensor is depleted.
2. Possibly the tire has slow air leak.
3. When the Tire pressure value is less than the warning threshold pressure value registered in the tire pressure monitor ECU.
4. Wheels other than the OEM spec are used.
5. Although the tire with tire pressure sensors are used, another tire set has been selected by the tire pressure warning switch.
6. The average life of the grommet of the TPM valve is 5 years which time must be replaced.
7. Re-tighten the valve nt if the valve is air leaking( check using soap buble method) and if it is less than 5 years, then grommet is not the problem.
8. Lastly the switch within the glove compartment change can be only done only if 2 Set of transmitter IDs are registered in the Tire pressure ECU, then either of the sets can be selected by changing the switch btw "Main & 2nd".
Hope this enlightens you the areas you need to look at to troubleshoot.

mrblister

I think he said that the light is always off no matter what position switch is in.

RCsGX

Have you had any shops mess w/ or re-register your sensors?




Mann777, I've seen you mention this switch twice now. I have an '05 as does the OP, there is no switch in the glove box. What exactly are you referring to? The only switch we have is the a/b that's under the steering wheel that allows you to program another set of wheels IE: a=summer / b=winter.

mrblister

I thought the same my 2004 has the a/b under the steering wheel as well. The op did say the light does not come on at all in either position . !!

mrblister

Only explanation for the switch not allowing the light to come in could be because the single set of tires is registered to both a and b if that is possible. If you let the air out quickly on one tire the light should come on that might be a good test to prove my possible theory

RCsGX

That's what I was thinking, that's why I asked if anyone has messed w/ them.

Maybe the system completely stopped working? Like you said...OP try and let some air out to see if the TMPS light comes on at all. If it does hit the a/b switch and see if it's still on.

lepoch

Thanks for all the replies, Last time the sensors were messed with was two years ago when I got new tires. SInce then, the light would come on if I had the switch in the wrong position.

I wonder if the spare is on A and the others are on B. I added air to all of them on Monday. I'm going to let some air out of one of the rear tires to see what happens.

thanks again.

mann777

Here is the location of the s/w. It will be mentioned as Main & 2nd. I have seen mine with the door of the glove comparment., Most of the GX 2004 -2007 models having the TPIS had within the glove compartment.
Another image attached if in case this helps.

RCsGX

Most don't have it there, most have it under the steering wheel. All of the newer Toyotas I've had and family members have had, the button has always been under or right beside the steering wheel. Mrblister above has an '04 too and his is under his steering wheel as well. Maybe your '04 is an early production run and they've since moved it or maybe they put it in the glove box on KDSS models?

It's weird because I've checked all of the owners manuals and they all show the switch under the steering wheel.

Here's mine:


I've also checked all manauls and they make no mntion of th

mrblister

My sc430 has the switch in the glove box. My gx470 is under the steering wheel. My manual also refers to it being there.

RCsGX

From the pic that Mann777 posted it looks to be in the spot of the CD changer so maybe Lexus puts it there if you don't have a CD changer?

IanB2

Mine's under the steering wheel as well.

As to the OP's question, the TPMS light won't be triggered until the system has failed on a couple of start-up cycles. When I first got my truck, I put new wheels/tires on it, and had the wheels/tires that came with the truck stacked in my basement. They were close enough that when I'd start the truck in the morning, the light wouldn't come on, even though as soon as I drove away the sensors would be out of range. I could usually go to my destination, shut off the truck, restart the truck and return home, without the light ever coming on. If I made multiple stops, or went for a long highway drive however, the TPMS light would be triggered.

mann777

I am actually surprised that some members have it the location mentioned by Rcgx ( thanks for letting me know). Probably the CD changer could have the option. But I had a friend from Ohio who had the Sporty GX 2007 model and he had the TPIS issues, and I clearly remember seen the switch within the glove compartment)
I do have most of the updated TSBs for GX models since 2003 by Lexus, and not one on the SBs mentioned for GX it says the TPIS location is below steering wheel nor the VIN number effective for certain GX models. More or less generalized to 2004-2007 GX models There are various SBs issued towards the TPIS issues and maintenance.
Note: After reading this email please don't request for email copies of the TSBs ( that could be a violation on the forum and infringement of Lexus Toyota technical material) I would refrain from doing that.