Hi all, my 2008 Rx400h is showing the low tire pressure warning. It flashes when I first start the car then goes solid. I took it to Les Schwab (PNW) and they said all 5 of my sensors read fine but the receiver is not programmable. It keeps crashing their programming software and they think it is a bad receiver.

So I’m trying to find what to replace. At Lexus parts they show two receivers. One in front and one in back.

https://parts.lexus.com/a/Lexus_2008_RX-400h/63399987__6731940/TIRE-PRESSURE-WARNING-SYSTEM/524410-8435.html

Anyone know what needs to be replaced and why?

 

They might be wrong. Sounds like one or more of your sensors is junk, that's all.
I suggest you go somewhere else, or figure out how to get Techstream on your own computer (PC), or, last resort, a Toyota dealer.
Do you know how old your TPMS sensors are?

 

As spinellib said, go to another place and ask them to check the sensors. Normally when the TPMS light blinks, it is because the battery in at least one of the tire sensors has died. Regular, standard maintenance for a car 10+ years old.

It is always possible that the receiver is bad, but they seem to be pretty reliable. So go do the easy thing first and go to another tire store and get the second opinion.

 

Isn’t there a second set of wheels button under the glove box? Someone probably kicked it.
That would be one reason that they can’t access the ECU. Also it is possible the ECU went into a closed loop because it thought it was being messed with. A properly formatted scan tool is required to get it out.

 

Thx all, I will get a 2nd opinion and yes working getting TechStream. I had checked the 2nd set of tire button and it’s in the correct position for main.

after I asked this question of which module, I thought about it more and think they are grouped per function in the picture. The top one (front) being for the 2 sets of tires and the lower (rear) for the TPMS connection.

 

You are sort of right. The rear unit is the radio receiver that the sensors in the wheels communicate with. The unit under the dash does everything else

 

Most tire store tools are pretty limited and not everyone knows how to use them. Hard to diagnose a bad receiver with them. I don’t think I’ve ever had a bad receiver issue in a Toyota/Lexus. Get a second opinion. If that scan tool can’t communicate with the ECU it probably went into lock mode. Where they able to pull codes?

 

Had the same thing happen last year, the tire pressures were correct & I was going to replace the tires, so I bought 4 new sensors & had Discount tire swap them out when installing new tires. One of the new sensors was bad, so ended up using the one good sensor w/ no issues & returned the bad sensor.

 

[QUOTE=BertDog;11246520]Thx all, I will get a 2nd opinion and yes working getting TechStream. I had checked the 2nd set of tire button and it’s in the correct position for main.

one time I couldn’t figure out why the 2nd set button made no difference so I dropped the lower panel to find out somehow the plug in the back was disconnected.

 

Solved this. Took the car to another tire shop and they confirmed all 5 sensors were good and had no other ideas. I bought a replacement TPMS ECU and replaced mine and now it is working properly. New part is $600-800 and on eBay it runs sound $100 used.