Low Air Warning Light On Dash

[Browninggold]

It's on. So I took my air compressor and put in 35#s of air in each tire. I put key to ON pos. and held the reset button until the 3 blinks were done. Light is still on. This is the first I have had to add air to the tires, usually the mechanic checks @ oil changes. They were low around 30#s. It's a 09', could it be a bad sensor or did I put too much air in the tires...does over inflated tire engage the light also? Thanks

[exmeaguy]

Being that you said you put 35#s of air in your tires, I assume you excluded the spare, which also has a sensor.

[Browninggold]

Just did front and back...had no idea the spare had a sensor. I'll check that thanks.

[James Horning]

Why did you " hold the reset button "?

That is to INITIALIZE the base tire pressure for the lamp to come on, you really should never have to touch this unless the threshold is set too high. You have now added a variable in this problem , does this car have a 2nd switch? Check that first , if you have a full spare it has a sensor . Deflate all tires to 25 psi , initialize the pressure by holding the switch , lamp goes out ... Inflate tire to door pressure or temperature compensated pressure 33 or 35 psi . Now you have at least 10 psi of pressure change before the lamp comes on. If you really don't know about this system please go to a dealer , get it diagnosed and repaired properly.

[Browninggold]

I held the reset after I filled the front and back tires @ 35lbs. The light was still on. I did not know the spare may also need inflated ( did not know spare had a sensor). This weekend I will put all tires @ 25lbs. and reset then I will put all tires @ 35 lbs. Thanks for the wealth of info very much appreciated.

[Browninggold]

Thanks for all the great info. Deflated all the tires including the spare. Did the reset and did the proper inflation of the tires. Warning light on dash is now off.

[tomx]

Guys,

I need your help! The low tire pressure light on my 2007 RX 350 was on during highway driving yesterday. I checked the tires right after that and found one of the aluminum tire valve caps was missing. All other 3 caps were very lose as well. I did the oil change the day before yesterday and I saw them added more air into the tires, so I believe they didn't tighten the valve caps :(

My question is - could the low tire pressure light be triggered by the missing valve cap?

BTW, I checked the tire pressure of all 5 tires including the spare tire and all of them were above 30 psi.

Also, I followed this thread and deflated all the tires including the spare. Did the reset and did the proper inflation of the tires to >30 psi. But the light is still on. When I turn on the engine, the light is just flashing for about 60 times and then keeps on.

Could this be the problem with sensors? Should I take the car to the dealer now? Any input is welcome, thanks a lot!

All the best,

Tom

[cduluk]

Guys,

I need your help! The low tire pressure light on my 2007 RX 350 was on during highway driving yesterday. I checked the tires right after that and found one of the aluminum tire valve caps was missing. All other 3 caps were very lose as well. I did the oil change the day before yesterday and I saw them added more air into the tires, so I believe they didn't tighten the valve caps :(

My question is - could the low tire pressure light be triggered by the missing valve cap?

BTW, I checked the tire pressure of all 5 tires including the spare tire and all of them were above 30 psi.

Also, I followed this thread and deflated all the tires including the spare. Did the reset and did the proper inflation of the tires to >30 psi. But the light is still on. When I turn on the engine, the light is just flashing for about 60 times and then keeps on.

Could this be the problem with sensors? Should I take the car to the dealer now? Any input is welcome, thanks a lot!

All the best,

Tom

Guys,

I need your help! The low tire pressure light on my 2007 RX 350 was on during highway driving yesterday. I checked the tires right after that and found one of the aluminum tire valve caps was missing. All other 3 caps were very lose as well. I did the oil change the day before yesterday and I saw them added more air into the tires, so I believe they didn't tighten the valve caps :(

My question is - could the low tire pressure light be triggered by the missing valve cap?

BTW, I checked the tire pressure of all 5 tires including the spare tire and all of them were above 30 psi.

Also, I followed this thread and deflated all the tires including the spare. Did the reset and did the proper inflation of the tires to >30 psi. But the light is still on. When I turn on the engine, the light is just flashing for about 60 times and then keeps on.

Could this be the problem with sensors? Should I take the car to the dealer now? Any input is welcome, thanks a lot!

All the best,

Tom

The loose/missing valve cap covers should not affect pressure at all (quite honestly their only function is to keep dirt out of there). Did they do anything else to the tires (rotate, etc) other than add more air?

Did you happen to accidentally/unintentionally press the push-button toggle switch below the glovebox? This switch allows you to toggle between two sets of tires (two sets of sensors if you wish to have a summer and winter set of wheels/tires/sensors). If the button is set to read a different set of tires, your car won't recognize your current set and would deliver the error light. Just a thought...

BTW the "reset" should never have to be done. If everything is working OK and you lose pressure or get a flat in one or two tires, your warning light should go on. At that point, all you'd need to do is inflate the tire and the light should go off. The reset only needs to be done under unique circumstances. More often than not, the reset ends up doing more harm than good.

[tomx]

No, they just added more air and changed the engine oil, nothing else.

I wish I didn't press the 'reset' button but I did that by following this thread :)

Also, I called my local Lexus dealer and told them the whole story. They asked me to inflate all 5 tires to 34 psi and I did, but the light is still on.

I will check the 'switch' button under the glove box tonight to see if that can fix the problem or not.

Thanks a lot for the input!

All the best,

Tom

The loose/missing valve cap covers should not affect pressure at all (quite honestly their only function is to keep dirt out of there). Did they do anything else to the tires (rotate, etc) other than add more air?

Did you happen to accidentally/unintentionally press the push-button toggle switch below the glovebox? This switch allows you to toggle between two sets of tires (two sets of sensors if you wish to have a summer and winter set of wheels/tires/sensors). If the button is set to read a different set of tires, your car won't recognize your current set and would deliver the error light. Just a thought...

BTW the "reset" should never have to be done. If everything is working OK and you lose pressure or get a flat in one or two tires, your warning light should go on. At that point, all you'd need to do is inflate the tire and the light should go off. The reset only needs to be done under unique circumstances. More often than not, the reset ends up doing more harm than good.

[tomx]

Finally I found the 'switch' button under the glove box. But no matter it's pushed in or out, the low tire pressure light is still on :(

[cduluk]

Finally I found the 'switch' button under the glove box. But no matter it's pushed in or out, the low tire pressure light is still on :(

K, i'd try the reset procedure again, and if that doesn't work then bring the car to the mechanic who added the air and see what they can do. Ultimately the Lexus dealer will be able to fix it but of course at a cost...