David Redfearn Posted May 10, 2006 Share Posted May 10, 2006 My IS-350 has pressure sensors in the wheels. If I calibrate the sensors to 35/37 PSI (standard inflation) how much can the pressure drop before the warning light comes on? My dealer indicated that they reset the sensors to 27/27 to reduce the number of alarms - but I want to keep the pressure correct. Quote Link to comment Share on other sites More sharing options...
Rx330driver Posted May 10, 2006 Share Posted May 10, 2006 i think that problem with the sensors are that they dont detect anything if very very small amounts of aire come out slowly. It will only tell you something if the pressure drops all of a sudden, like a blown tire. Quote Link to comment Share on other sites More sharing options...
steviej Posted May 10, 2006 Share Posted May 10, 2006 i think that problem with the sensors are that they dont detect anything if very very small amounts of aire come out slowly. It will only tell you something if the pressure drops all of a sudden, like a blown tire. well that makes no sence at all. If I blow a tire, I don't need some little sensor to tell me the tire instantly went flat. I thought these sensors or systems were to tell you when the pressure drops gradually over time. For example if I had a slow leak due to a nail or faulty valve stem. Dave, what is said in the manual? steviej Quote Link to comment Share on other sites More sharing options...
Rx330driver Posted May 10, 2006 Share Posted May 10, 2006 perhaps im wrong, but i thought i remembered somebody saying that on this forum...but i guess the TPM would be pointless in that case. i retract my statement Quote Link to comment Share on other sites More sharing options...
mehullica Posted May 10, 2006 Share Posted May 10, 2006 Light should come on around 27 psi. Quote Link to comment Share on other sites More sharing options...
bartkat Posted May 10, 2006 Share Posted May 10, 2006 People have reported the tire pressure warning coming on around 25-26 PSI. Quote Link to comment Share on other sites More sharing options...
David Redfearn Posted May 14, 2006 Author Share Posted May 14, 2006 People have reported the tire pressure warning coming on around 25-26 PSI. So, if the tire pressure sensors are calibrated to 35 PSI, it takes a 10 PSI drop to have the alarm come on? That seems to be a big drop - this car can run at 100 MPH easily - I would not want to run at 80+ with the tires inflated to 25 PSI. I'm going to see what the dealer says...... David Quote Link to comment Share on other sites More sharing options...
bartkat Posted May 14, 2006 Share Posted May 14, 2006 People have reported the tire pressure warning coming on around 25-26 PSI. So, if the tire pressure sensors are calibrated to 35 PSI, it takes a 10 PSI drop to have the alarm come on? That seems to be a big drop - this car can run at 100 MPH easily - I would not want to run at 80+ with the tires inflated to 25 PSI. I'm going to see what the dealer says...... David Beats not having any sensors at all. They probably don't expect you to run at sustained speeds of 100 MPH anyhow. Quote Link to comment Share on other sites More sharing options...
highgate Posted May 16, 2006 Share Posted May 16, 2006 People have reported the tire pressure warning coming on around 25-26 PSI. So, if the tire pressure sensors are calibrated to 35 PSI, it takes a 10 PSI drop to have the alarm come on? That seems to be a big drop - this car can run at 100 MPH easily - I would not want to run at 80+ with the tires inflated to 25 PSI. I'm going to see what the dealer says...... David Beats not having any sensors at all. They probably don't expect you to run at sustained speeds of 100 MPH anyhow. I have an IS 350 my tire sensor went off yesterday. My driverside rear tire was down to 30psi. I had been told that a 5psi drop will activate the sensor. The sensors are not as sophisticated as my prior vehicle an Audi Allroad which identified the specific tire when the psi droppped. Quote Link to comment Share on other sites More sharing options...
Bourne33065 Posted May 20, 2006 Share Posted May 20, 2006 My tire sensors went off day before yesterday, it was down to like 25 30 something like that. As soon as I got into the car they went off, I think they do a good job. But I have no idea how the pressure dropped that far so suddenly on all four tires.... Quote Link to comment Share on other sites More sharing options...
jPAUL Posted June 25, 2006 Share Posted June 25, 2006 i dont wanna see that sensor nemore... my tires got nailed twice in less than 3 weeks after i got my IS. Quote Link to comment Share on other sites More sharing options...
Lance Van Buren Posted May 27, 2008 Share Posted May 27, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly? Many thanks... LVB Quote Link to comment Share on other sites More sharing options...
clay1 Posted May 27, 2008 Share Posted May 27, 2008 i think that problem with the sensors are that they dont detect anything if very very small amounts of aire come out slowly. It will only tell you something if the pressure drops all of a sudden, like a blown tire. The sensors are great. Both times they went off I thought false alarm because tires looked fine. Wrong both times nails both times. In fact the first time it was so small without a head the dealer didn't see it unless the sensor went off again. Since I drive 100 miles a day they saved me from being stuck on the side of the road both times. Quote Link to comment Share on other sites More sharing options...
bartkat Posted May 28, 2008 Share Posted May 28, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly?Many thanks... LVB The sensors stay in the wheels. If you don't have an alarm then they are ok. Quote Link to comment Share on other sites More sharing options...
tex2670 Posted May 28, 2008 Share Posted May 28, 2008 People have reported the tire pressure warning coming on around 25-26 PSI. So, if the tire pressure sensors are calibrated to 35 PSI, it takes a 10 PSI drop to have the alarm come on? That seems to be a big drop - this car can run at 100 MPH easily - I would not want to run at 80+ with the tires inflated to 25 PSI. I'm going to see what the dealer says...... David Just like you may not want to wait until your oil light comes on, just because you have a TPMS doesn't mean you shouldn't still manually check your tire pressure. Personally, I would not want it coming on for 1 or 2 PSI change. Quote Link to comment Share on other sites More sharing options...
Gaugster Posted May 28, 2008 Share Posted May 28, 2008 People have reported the tire pressure warning coming on around 25-26 PSI. So, if the tire pressure sensors are calibrated to 35 PSI, it takes a 10 PSI drop to have the alarm come on? That seems to be a big drop - this car can run at 100 MPH easily - I would not want to run at 80+ with the tires inflated to 25 PSI. I'm going to see what the dealer says...... David Beats not having any sensors at all. They probably don't expect you to run at sustained speeds of 100 MPH anyhow. Actually, the FM states that if you will be driving at high speeds (~100MPH), you should increase the tire pressure. I think is was about 7-9psi above the normal specs of 35/37psi F/R. So with the higher pressure as the TPMS reference. A 10psi drop would put the warning pressure at around 35psi. Regards, Quote Link to comment Share on other sites More sharing options...
Lance Van Buren Posted May 28, 2008 Share Posted May 28, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly?Many thanks... LVB The sensors stay in the wheels. If you don't have an alarm then they are ok. Bartkat - thanks for the information; I was worried that I lost my sensor capability. No alarms, but I will go check the air after work... Thanks LVB Quote Link to comment Share on other sites More sharing options...
bartkat Posted May 28, 2008 Share Posted May 28, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly?Many thanks... LVB The sensors stay in the wheels. If you don't have an alarm then they are ok. Bartkat - thanks for the information; I was worried that I lost my sensor capability. No alarms, but I will go check the air after work... Thanks LVB I had 4 tires put on with no sensor problems. Then I adjusted the PSI in the tires to what I wanted and everything is just fine. Quote Link to comment Share on other sites More sharing options...
maggie1 Posted June 1, 2008 Share Posted June 1, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly?Many thanks... LVB The sensors stay in the wheels. If you don't have an alarm then they are ok. Bartkat - thanks for the information; I was worried that I lost my sensor capability. No alarms, but I will go check the air after work... Thanks LVB I had 4 tires put on with no sensor problems. Then I adjusted the PSI in the tires to what I wanted and everything is just fine. Lexus told me the tire pressure changes with the weather winter/summer (cold/hot) Quote Link to comment Share on other sites More sharing options...
frogs9497 Posted June 1, 2008 Share Posted June 1, 2008 This may be a dumb question, but I had my tires replaced (2005 LS430) from a "non-dealer" source and I'm wondering: did they reinstall the tire pressure sensors? My understanding is that the sensors are actually a part of the air valve...should I be concerned and am I even considering this correctly?Many thanks... LVB The sensors stay in the wheels. If you don't have an alarm then they are ok. Bartkat - thanks for the information; I was worried that I lost my sensor capability. No alarms, but I will go check the air after work... Thanks LVB I had 4 tires put on with no sensor problems. Then I adjusted the PSI in the tires to what I wanted and everything is just fine. Lexus told me the tire pressure changes with the weather winter/summer (cold/hot) I would second that... here in Texas, we occasionally have wild swings in temperature (from HOT to COLD) in a day. I've had tire pressures drop 6-8 psi in a matter of hours, causing the sensor to light up. Quote Link to comment Share on other sites More sharing options...
playcaller Posted June 1, 2008 Share Posted June 1, 2008 If they were to come on for a 1-2 PSI change you would get a lot of "false" alerts in the winter. Assuming you live where there actually is a winter. Subfreezing temperatures can lower a tires PSI and your monitor will go off until friction increases the PSI while driving. Quote Link to comment Share on other sites More sharing options...
bartkat Posted June 1, 2008 Share Posted June 1, 2008 I think the rule is that tire PSI will change by 1 PSI with every 10 degrees F change in outside temperature. Quote Link to comment Share on other sites More sharing options...
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