LorizRX350

Anyone with aftermarket wheels have any issue's with the tire pressure sensors? We just put some wheels on the RX350, and it doesn't seem the tire pressure sensors are working anymore.

Also, how does this tire pressure sensor system work exactly? I've only heard assumptions to it being a remote system via a remote sensor connected to the valve stem. Is this because of the aftermarket wheels? Did the shop break them by chance when swapping with the stock wheels? Is there a way to adjust the psi to where it will throw the idiot light?

I have several questions about this, so anyone who could give me a hand would be greatful.

VroomVroom

Only because I just read it myself...there's a lot of great info about the TPMS in the owner's manual. Including how to reset the system following a tire change.

However, from the content of your post I'm guessing the wheel shop didn't reuse the sensors when mounting your wheels. If not, the first question you'll want to ask is whether or not the wheels are compatible with the sensors. I'd start by going back to the shop and talking with someone with general knowledge on the TPMS systems. Good luck...

LorizRX350

I did a brief look through of the owners manual, and didn't find anything. I'll have to look again.

I don't know what the sensors look like, or how they work exactly, but I was told the sensors are connected to the valve stems, and I know the valves stems on the stock wheels were swapped onto the 20's. Granted that wouldn't make sense why they'd do that if the sensor wasn't installed as well, but it really doesn't prove it either.

But if the system doesn't find a sensor to be located, does it automatically throw the dumby light, or does it not do anything?

I'll have to look at the owners manual again.

VroomVroom

Hopefully it's just a matter of recalibrating. If memory serves (which it probably doesn't, so have your manual handy) I believe you just hold down the dash button for three seconds. Good luck...

mandyfig

The sensor is tied to the speed resistance as explained by somebody earlier. It measures the drag between the 4 wheels and senses that a wheel has higher rolling resistance because of low air pressure. It activates after 20 mph(??)

jim256

Since you have an RX 350, you'll need to explore the manual or the dealer to determine if you have a direct read system or the one described by mandyfig which uses the ABS sensors to measure each wheel's rotations. Lexus went from that indirect system to direct read either with the 350, or perhaps with the '07 model year. I'm not sure whether all '07's were RX 350's.

The G Man

LorizRX350, looking at your name, I assume u have a 07 RX or 08. The 07 and up use direct TPMS. Each wheel has a sensor in it. Make sure you have the TOMS sensors in the new wheels. You can tell by looking at the neck if the valve stem. If it is made out of metal, then it has the sensor in it. I would also test out the TPMS by bleeding down the spare tire to maybe 15 PSI and then drive around for a while to see if the light comes on. If it doesnt, then I would try to reset the TPMS system. If all that dont work, then you will need a trip to the dealer.

Good Luck

gwong

You need to take vehicle to dealer and have the new sensors registered to the tire sensor system.

The G Man

He swap the sensors, he didnt buy new ones.

LorizRX350

The sensors were swapped... at least the valve stems were. I'm going to buy new sensors to put back on the stock wheels so when I do swap for winter months, I won't have to dismount the tires from the wheels everytime I want to swap the wheels. It'll just be an at-home job.

I don't know the whole chain of events, but Lori did have a flat tire once that she noticed in a parking lot, and low tire light was on. I don't know if it was low/flat when she pulled in and didn't notice till later, or what happened.

In current form with the 20's, I did lower one of the tires down to 20 psi, and nothing came on. I did roll it back and forth in the driveway, and nothing came on. I will have to take it to the street and see if it works above 20mph to eliminate that.

And it's an '07 RX350.

The G Man

When you get the new sensors for your stock/winter wheels, you will have to go to the dealer to have them program it into the TPMS computer.

mandyfig

Looks like there is a transmitter on the valve stem? Similar to what you can find on the valve stems that tell you pressure, except that this has a powered transmitter?

LorizRX350

Is that gonna cost G Man? I guess I don't know how this sensor works at all. Is it battery powered? Is it removable from the valve stem?

The G Man

It is battery powered and it is part of the valve stem assembly. Last time I check, programming in additional sensors is not a freebie, I think its like a $150.

LorizRX350

Good grief... guess I'll leave that up to her then, heh. I like gadgets, but goodness.