Darel

This seems to come up here from time to time. Last year when I rotated my tires it took 3-4 days for "Tire Pressure Monitor Active" to go away and for me to get my direct readings on the TPMS back. Now, it's been 3 weeks since I rotated my tires and I've pretty much given up on my tire pressure display coming back.

Have we determined yet, if this is the result of the batteries in the sensors dying, and replacement of the sensors is the fix? If so that's fine, but I don't feel like spending $150 on sensors plus remount and balance only to find that's not the issue.

Car has about 64,000 miles and is covered under CPO extended warranty. Has anyone ever gotten the sensors replaced under warranty?

Thoughts?

Jan AMG

Darel

Yeah, this is almost a month and about 2,000 miles. So is this a normal indicator of the sensor batteries dying?

Jan AMG

Darel

No, no warnings. Just "Tire Pressure Monitor Active" for almost a month now.

DFWdude

I would use the manual process to reset the TPMS values to see if that works.

Various You-tube videos state that battery life should be 7-10 years. So, IMO on a 4-year old car, the batteries should not be exhausted, yet.

Darel

What's the manual retraining procedure? Don't recall that coming up before.

ItalianJoe1

You did reset them via the dash right?

If it says active and no yellow warning, they all have to be working. It's strange that it won't show you the location. Normally it pops up within the first mile or 2 of driving once temperatures stabilize.

Darel

Yes, I did reset them initially .I think I tried it one more time a week or two ago as well. Yeah, I have no warnings or anything. After reading up on this quite a bit the system should still warn me if something depressurizes, but it just doesn't show the individual values.

KEY08

thefisch

OP, I had the same issue about 2 years ago. https://mbworld.org/forums/e-class-w...each-tire.htmlIt took about 2 months before the individual tire readings came back. In the meantime, the system is active and monitoring but can't locate the position of each tire.

The chances of all 4 sensor batteries going bad at the same time are slim. If only 1 or 2 tires didn't show up then, I could understand suspecting the batteries. Plus, when a battery is bad I believe the warning light comes on because there is no reading at all (like when you have the spare tire on). If you want to check on the batteries, go to a tire shop with one of those sensor readers to check the pressure reported by each sensor. If they are able to get a quick reading off each sensor, then the batteries are fine. If their reader fails to get a reading or takes several attempts, then the battery might be low or dead in that sensor.

Darel

Thanks, I recall referring to your post the last time this happened, but then my pressures came back after just a few days.

Two months, huh? Guess I'll just wait .

Considering taking it in to the dealer to see if they'd check it out under warranty. Can't imagine what would be wrong, but something isn't right.

thefisch

Yeah, mine was not under warranty so the dealer would have checked SDS for a diagnostic fee. I was waiting for my next service and it happened to come back for no reason. I've rotated the tires about 3-4 times since then and not had the same issue. Strange.

Darel

In case anyone's following, my pressures came back today. Did the rotation on 4/22.

KEY08

thefisch

Thanks for updating the thread and glad they came back.