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Having owned a few Toy/Lex vehicles equipped with TPMS, I was under the impression that it takes 3-5 psi below spec to trigger a TPMS caution. BTW, these Continentals don't seem to naturally diminish pressure over time; I check them carefully and often, especially with large OAT swings. In about two years of ownership, I have not had to make seasonal adjustments for the most part. I have never grasped the apparent fact that the TPMS readings may not be spot-on.
The 2106 RX 450H seems to be a different animal. I've been Ignoring my 30 psi cold reading w/ amber caution for a few days (it's three tires). They rise to 31 or 32 with heat friction, but the caution remains. I just aired all 4 to 33 psi, and the dash reading does not match. I went back and re-checked all four with the digital gauge. Each was 33.1 or 33.2. However, TPMS continues to show one is at 34, the others 31-32. My digital gauge attached to my compressor is historically very accurate, matching the very expensive TPMS in our motor home, as well gauges used by major tire retailers. So now I am questioning the accuracy of the RX TPMS, and I'm wondering why the caution will not go away with all four tires +/- 1 or 2 of the factory spec, be it accurate readings or not. I haven't taken it for a drive yet. But I will, looking for the indicated pressures to rise and reset the caution. Interested to hear from others if they've had relatable experiences.
I don't depend on TPMS to alert me of anything except a flat tire. I have an accurate manual gauge that I set all 5 tires at the correct cold tire pressure and I adjust it depending on the time of year, i.e. summer vs winter.
Yes, you are correct. It is not accurate and so is anything else. There will be always a limitation to accuracy.
I'm sure you are correct. But since I've owned the RX, TPMS showed four matched pressures, with an occasional 1 psi drift on a single tire. Of course this variation seemed to be influenced by driving. These indications were cross-checked by tire shops when taken in for rotation and by me. So, I had developed this notion that these indicators were pretty much spot-on. I guess I'm rather OCD, in that I like matched "needles" on the instruments, whether its a car, truck, airplane or boat. I suppose I just need to scroll the page so I don't see the TPMS
11782882[/url]]I'm sure you are correct. But since I've owned the RX, TPMS showed four matched pressures, with an occasional 1 psi drift on a single tire. Of course this variation seemed to be influenced by driving. These indications were cross-checked by tire shops when taken in for rotation and by me. So, I had developed this notion that these indicators were pretty much spot-on. I guess I'm rather OCD, in that I like matched "needles" on the instruments, whether its a car, truck, airplane or boat. I suppose I just need to scroll the page so I don't see the TPMS
The PSI variance is due to heat. You may pump all tires to 33 psi. However, when it is hot, the fronts will register higher due to engine heat.
Bump - Tired of the TPMS. I looked for deactivation tips on the forum, but have not found anything. Is there a fuse to pull that would terminate the caution when erroneous psi levels are reported?
The low-pressure warning thresholds were set too high when the monitor was initialized. Perform the tire pressure monitor initialization process, make sure the base pressures are correct before beginning. The low-pressure thresholds can be reviewed using Techstream. If the system was initialized while the tires were inflated to 38 psi, the low-pressure warning will occur @ 32 psi. That causes an annoyance.
The low-pressure warning will alert when the pressure drops 6 psi below the base pressure. Once the warning appears, the pressure must increase more than 2 psi to cancel the warning, this is why you might not see the warning go away from minor pressure increase while driving.
The low-pressure warning thresholds were set too high when the monitor was initialized. Perform the tire pressure monitor initialization process, make sure the base pressures are correct before beginning. The low-pressure thresholds can be reviewed using Techstream. If the system was initialized while the tires were inflated to 38 psi, the low-pressure warning will occur @ 32 psi. That causes an annoyance.
The low-pressure warning will alert when the pressure drops 6 psi below the base pressure. Once the warning appears, the pressure must increase more than 2 psi to cancel the warning, this is why you might not see the warning go away from minor pressure increase while driving.
Bump - Tired of the TPMS. I looked for deactivation tips on the forum, but have not found anything. Is there a fuse to pull that would terminate the caution when erroneous psi levels are reported?
I guess one way to stop the "cautions" would be to temporarily deflate the tires to around 28-30 psi, initialize, and then reinflate back up to your usual pressure. I for one, have always seen the TPMS readings on my 2017 agree closely with my digital gauge.
Is it possible new tpms sensors would correct this? I’ve never had any issues with ours!
I'm not sure. But it does not seem worthwhile to pursue, just to see if it works. I've done this on other vehicles and had mixed results. Across several brands, including Toyota and Lexus, I have never seen equally inflated tires (checked closely with a verified "good" gauge) report such widely ranging and false numbers. I'm willing to replace sensors when the battery dies or one sensor is obviously failing, but an entire set for "crying wolf," no.
TPMS Caution Threshold
