TPMS questions

[PatSC23]

Saw a few posts on it but none of them seemed to directly answer my questions - need some help from those more familiar with the system. Had the Modulares put back on yesterday, reset TPMS. Drove for 2 miles and low pressure indicator came on. Checked pressures and my right front was @ 28 psi - assuming it wasn't inflated properly. Pumped it back up to 39 and drove a bit but the error AND message did not clear. I proceeded to reset it on my drive home, which was only 2 miles. When I got home I checked the right front and it was still at 39, so it wasn't leaking air. My questions are 1.) do you need to drive around for a while for the system to reset after you do the manual reset? Was I being too impatient? I did reset multiple times on way home because the error didnt clear right away. 2.) If the TPMS were faulty - wouldn't I get a different warning other than "Low pressure" (saw that regular W204 gives an inoperable warning) 3.) When you reset the system, does the error and message stay on until the system recognizes the new psi, or should it go away immediately even while it calibrates? Thx!

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[I am Jeff]

Your TPMS is set at to trigger if it falls below a certain threshold. If your new modulares are inflated at a higher or lower pressure, driving around in them will do nothing to reset the system. You have to reset the TPMS for the specific pressure amount you have on your modulares and then drive around in them. The low pressure warning should disappear right after that.

[PatSC23]

Originally Posted by I am Jeff

Your TPMS is set at to trigger if it falls below a certain threshold. If your new modulares are inflated at a higher or lower pressure, driving around in them will do nothing to reset the system. You have to reset the TPMS for the specific pressure amount you have on your modulares and then drive around in them. The low pressure warning should disappear right after that.

Yea it didn't immediately clear after a manual reset, the warning and message is still on as of last night. But if it weren't working, then I dont think I would have gotten the first warning which was correct b/c my right front was at 28 psi only. Hopefully I was just being too impatient and not giving the system enough time to reset.

[PatSC23]

So its not resetting at all. Does that mean one of my sensors are bad? Who created a system where you need to take each TPMS sensor off the tire to see if it's broken?

[motoman]

JEff's experience is also mine. The original sensors are still on the Hankook summers and unamed sensors on the Michelin Alpines. I run both sets at 39/47. In winter wife sometimes reports warning whereupon I find one tire (usually front)
down about 1 pound. Adding 1 pound usually resolves warning light. This spring, for instance, I was able to put the Hankooks back on set at above pressures . Wife mentioned warning light leaving first day, but resolved on way back without reset.

[PatSC23]

Turns out my TPMS sensor was cracked. It finally broke off and I could hear it in the wheel, but didnt drive on it. The tire also went flat bc the sensor would no longer hold in air at the valve. Had all four replaced and Im good to go now.

On a side note - Reminder guys - DO NOT use metal caps on the TPMS valve stems!