TPMS not displaying values, but low tire pressure light not on
08-25-22, 01:57 PM
#16
See post #13.
I've had the dashes for well over a year, even after I spent $1600 on new PS4 rubber. Air them up stone cold, 2 PSI or whatever over recommended. Mine came back on and have been OK for a few months.
As others have posted, this makes no sense.
Good luck.
I've had the dashes for well over a year, even after I spent $1600 on new PS4 rubber. Air them up stone cold, 2 PSI or whatever over recommended. Mine came back on and have been OK for a few months.
As others have posted, this makes no sense.
Good luck.
08-25-22, 04:12 PM
#17
Bringing back a necro thread since there's nothing like this in the GS F forum. I got all new sensors today because the tire tech broke one of the OEM units (yeah, he's definitely not qualified for his job) and I registered them myself using Techstream. They all show up there indicating pressure, temperature, and good battery. They don't show up in the display on the dash at all. This makes zero sense to me. There's nothing in TIS to help understand this either.
RE: post above - this has not been my experience with my IS F at all. They've just worked, and I've been through two sets of wheels and three sets of sensors. I've never had them fail unless I put on my second set of wheels and didn't change from the previous set.
RE: post above - this has not been my experience with my IS F at all. They've just worked, and I've been through two sets of wheels and three sets of sensors. I've never had them fail unless I put on my second set of wheels and didn't change from the previous set.
08-25-22, 05:13 PM
#19
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A couple of things here. Haven’t checked on an IS in a minute but on my GS 95% of the time I need to put the car in drive and start moving for the dashes to go away. Also, if they gave you the incorrect part it’s possible to turn the light of and see the pressures on a scan too but the vehicle won’t show them
Took the car for a 40 minute drive around town. Still nothing on the display. The pressures have always been shown when I started the car, never had to wait for them to show up. I've had the GS F since October 2016, so I'm pretty familiar with normal.
Last edited by lobuxracer; 08-25-22 at 05:18 PM.
08-25-22, 08:03 PM
#20
On Techstream? Not "a scan tool", but the full blown Lexus dealership tool to test and diagnose all OBD related problems with Toyota/Scion/Lexus since 1989. It doesn't read the sensors directly, it reads the output of the TPMS ECU through the OBDII port. I have a professional subscription to this which also gives full access to TIS. There's nothing about this in TIS at all.
Took the car for a 40 minute drive around town. Still nothing on the display. The pressures have always been shown when I started the car, never had to wait for them to show up. I've had the GS F since October 2016, so I'm pretty familiar with normal.
Took the car for a 40 minute drive around town. Still nothing on the display. The pressures have always been shown when I started the car, never had to wait for them to show up. I've had the GS F since October 2016, so I'm pretty familiar with normal.
08-25-22, 09:00 PM
#21
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Who is they? Lexus? Lexus uses the two antennas to determine location of the sensors. There's no ability to enter the sensor data with any indication of where the sensor is. The utility just tells you to enter the codes (all four every time) and the rest is done by the physical layout of the antennas and the TPMS ECU. This is the same on the IS F and the GS F. You are missing a significant point here. I am not using a scan tool for pressure sensors. I am connecting to the OBDII port and reading the values the TPMS ECU is receiving from the sensors. I can see the pressure, temperature, and battery status of all the sensors through this interface as read by the TPMS ECU. Techstream has no ability to directly read a 315 MHz radio signal coming from any of the sensors. It can only read what is stored in the TPMS ECU which does have antennas to capture the signals from the sensors. So it makes no sense why the TPMS ECU sees and displays the pressures but fails to put them on the CANBUS for the Combination Meter to display. That's what is happening in detail.
08-25-22, 09:53 PM
#22
Who is they? Lexus? Lexus uses the two antennas to determine location of the sensors. There's no ability to enter the sensor data with any indication of where the sensor is. The utility just tells you to enter the codes (all four every time) and the rest is done by the physical layout of the antennas and the TPMS ECU. This is the same on the IS F and the GS F. You are missing a significant point here. I am not using a scan tool for pressure sensors. I am connecting to the OBDII port and reading the values the TPMS ECU is receiving from the sensors. I can see the pressure, temperature, and battery status of all the sensors through this interface as read by the TPMS ECU. Techstream has no ability to directly read a 315 MHz radio signal coming from any of the sensors. It can only read what is stored in the TPMS ECU which does have antennas to capture the signals from the sensors. So it makes no sense why the TPMS ECU sees and displays the pressures but fails to put them on the CANBUS for the Combination Meter to display. That's what is happening in detail.
08-26-22, 02:47 PM
#23
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I understand what you are saying, but these sensors fit a massive range of Lexus applications according to the manufacturer. The part number for them is common across a very wide range of years, so I would expect LOTS of complaints about them if they didn't display properly. I did check in TIS's training section and the system uses a single antenna, unlike the IS which uses two. Some models have 4. So, you are saying there is data coming from the sensor itself to help the ECU know where it is? Is it possible I could enter the codes in a different order and it would resolve the positioning issue? There's nothing in Lexus service manuals or training telling me this would work, but it's not hard to try.
08-26-22, 03:21 PM
#24
Reading through most of the post it would be my opinion, that there is something wrong with those Sensors. Are they Toy/Lex Brand from Dealer sensors? The sending signal is all about Frequency.
Go see Chris the Manager at Sugarloaf Mills Discount tires. He's good. I got done with NTB when they changed over. I had a similar problem where my Sensor after a Rotation were reading the wrong position. They corrected it. It was not my Lexus though. It was my Charger.
Go see Chris the Manager at Sugarloaf Mills Discount tires. He's good. I got done with NTB when they changed over. I had a similar problem where my Sensor after a Rotation were reading the wrong position. They corrected it. It was not my Lexus though. It was my Charger.
Last edited by jgscott; 08-26-22 at 03:25 PM.
08-26-22, 03:45 PM
#25
I understand what you are saying, but these sensors fit a massive range of Lexus applications according to the manufacturer. The part number for them is common across a very wide range of years, so I would expect LOTS of complaints about them if they didn't display properly. I did check in TIS's training section and the system uses a single antenna, unlike the IS which uses two. Some models have 4. So, you are saying there is data coming from the sensor itself to help the ECU know where it is? Is it possible I could enter the codes in a different order and it would resolve the positioning issue? There's nothing in Lexus service manuals or training telling me this would work, but it's not hard to try.
I doubt inputting them Ina different order would change much but technically they should be entered in LF, RF,RR,LR. Once they are stored in the ECU pushing the reset button would correct any location or pressure issues. It really sounds like you have the wrong sensors. Most Lexus part numbers change when the model year starts displaying actual pressure per location. The wrong ones will most likely program but won’t show pressures. Some of the part number differences are only the angle of the valve stem but some it’s the way they transmit. It doesn’t make sense that a proper scan tool will read the actual pressure but the sensor will still be wrong and not display in the car but it’s a true statement. Lots of post here and hard to pull it up while I’m typing on my phone but give me the year/make/model again and part numbers that were used
08-26-22, 04:04 PM
#26
Hmm,
I doubt inputting them Ina different order would change much but technically they should be entered in LF, RF,RR,LR. Once they are stored in the ECU pushing the reset button would correct any location or pressure issues. It really sounds like you have the wrong sensors. Most Lexus part numbers change when the model year starts displaying actual pressure per location. The wrong ones will most likely program but won’t show pressures. Some of the part number differences are only the angle of the valve stem but some it’s the way they transmit. It doesn’t make sense that a proper scan tool will read the actual pressure but the sensor will still be wrong and not display in the car but it’s a true statement. Lots of post here and hard to pull it up while I’m typing on my phone but give me the year/make/model again and part numbers that were used
I doubt inputting them Ina different order would change much but technically they should be entered in LF, RF,RR,LR. Once they are stored in the ECU pushing the reset button would correct any location or pressure issues. It really sounds like you have the wrong sensors. Most Lexus part numbers change when the model year starts displaying actual pressure per location. The wrong ones will most likely program but won’t show pressures. Some of the part number differences are only the angle of the valve stem but some it’s the way they transmit. It doesn’t make sense that a proper scan tool will read the actual pressure but the sensor will still be wrong and not display in the car but it’s a true statement. Lots of post here and hard to pull it up while I’m typing on my phone but give me the year/make/model again and part numbers that were used
08-26-22, 10:36 PM
#27
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So the only thing left is the sensors. They do show up, they do show actual pressure (I tested each of them and determined which sensor was on which wheel, then reordered them in the tool to LF RF RR LR. They failed the signal check for diagnostics on all four sensors, failed the position check, and failed the initialization switch test. TIS says to drive over 30 mph for one minute to try and clear the DTCs set by the test and this did nothing as well.
All the reputable sources want $70 a piece for these sensors. Glad I didn't let the tire shop toss the three remaining good ones. I'm just irritated I'll be putting one new sensor in with three sensors that already have almost 6 years of service on a projected 10 year service life.
All the reputable sources want $70 a piece for these sensors. Glad I didn't let the tire shop toss the three remaining good ones. I'm just irritated I'll be putting one new sensor in with three sensors that already have almost 6 years of service on a projected 10 year service life.
08-26-22, 11:24 PM
#28
So the only thing left is the sensors. They do show up, they do show actual pressure (I tested each of them and determined which sensor was on which wheel, then reordered them in the tool to LF RF RR LR. They failed the signal check for diagnostics on all four sensors, failed the position check, and failed the initialization switch test. TIS says to drive over 30 mph for one minute to try and clear the DTCs set by the test and this did nothing as well.
All the reputable sources want $70 a piece for these sensors. Glad I didn't let the tire shop toss the three remaining good ones. I'm just irritated I'll be putting one new sensor in with three sensors that already have almost 6 years of service on a projected 10 year service life.
All the reputable sources want $70 a piece for these sensors. Glad I didn't let the tire shop toss the three remaining good ones. I'm just irritated I'll be putting one new sensor in with three sensors that already have almost 6 years of service on a projected 10 year service life.
Next, once the sensors are programmed to the ECU the ECU will search for them and wait for a signal, that’s why it’s saying to drive it. If it doesn’t receive the signal within a certain amount of time you won’t be able to retrieve the ID’s from the ECU because the procedure wasn’t completed. The work around is once the ID’s are programmed to the ECU without turning the car off you need to scan each sensor with a tpms scan tool so that it forces the signal to the ECU starting with the LF, RF, RR,LR sequence.
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lobuxracer (08-27-22)
08-27-22, 02:16 AM
#29
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Thanks for the expert assistance. I'm frustrated with the possibility the sensors can be reporting data but not be able to provide RTD to the display. New sensor(s) are on the way, and I will install them with the expectation Lexus won't sell me a sensor incapable of both turning off the TPMS light AND providing real time data to the display. Thanks for the assistance, sorry it was so challenging to realize the system is so fragile.
08-27-22, 08:33 AM
#30
Lob, I just talked to Chris at DT. I had to speak with him about something else too. He said it likely those Sensor are not compat with your car. He said there was a year like 13, 14, 16 of the GS that only will work mostly with the Factory sensors only. So... IDK but that's what he says. Chris is a good guy to work with there at DT. After I have done a few tire buys and other, he actually does things like this for me for free. He a mod car Guy himself. Good Luck!