TPM Life

[rvnmaniac]

My 2009 2.5i SE with almost 67,000 miles now has a TPMS light on. I immediately checked the tires for pressure and all are fine. Just curious what life others have on their TPMS. It's a good possibility these are the originals. I just purchased the car Jan of this year, so don''t have any history other than I'm the 2nd owner. Black electrical tape works fine for getting rid of the light, wink, wink. Not too concerned about replacing the TPM right now since i have other rims I'll be putting on shortly and already purchased new OEM TPMS for those rims.

[08SpecB_DE]

If they light blinks then goes solid, it is a sensor or calibration issue. If you start the car and it just lights up solid, it's a pressure issue.

[Max Capacity]

My 09 had two batteries die earlier this year right after having new tires mounted. A piece of black electrical tape covers the light so I don't see it.

[CapnJack]

If they light blinks then goes solid, it is a sensor or calibration issue. If you start the car and it just lights up solid, it's a pressure issue.

 

This...

 

The sensor batteries last about 5-7 years. I just replaced two this year on my 2008. I used the Schrader EZ sensor and cloned the new one from the old one.

 

Unless the battery in the TPMS sensor has completely failed, it's a PITA to figure out which one it is because of the lack of battery level feedback from the sensor to most TPMS tools. Typically, there is enough power left in the battery to tell the tool it's good, but not enough to keep the TPMS light on the dash out. I'm not sure even the SSM at Subaru can tell which one is bad? (at least not for less than the minimum typical hook up charge of $50) You'll likely end up having to play "wack-a-mole" to figure out which one it is and replace one at a time until the light goes out if you want to replace it.

 

As was mentioned, if the light comes on and just stays on, it's a pressure issue. Over inflation will cause this as will under-inflation.

[theflystyle]

My stock sensors lasted nearly 10 years. After reading about them, it was stated to have a lifespan of about 10 years/100,000 miles.

[rvnmaniac]

My stock sensors lasted nearly 10 years. After reading about them, it was stated to have a lifespan of about 10 years/100,000 miles.

 

Thanks that was pretty much my question.. My tires are all showing and holding the correct tire pressure.

[Max Capacity]

This...

 

The sensor batteries last about 5-7 years. I just replaced two this year on my 2008. I used the Schrader EZ sensor and cloned the new one from the old one.

 

Unless the battery in the TPMS sensor has completely failed, it's a PITA to figure out which one it is because of the lack of battery level feedback from the sensor to most TPMS tools. Typically, there is enough power left in the battery to tell the tool it's good, but not enough to keep the TPMS light on the dash out. I'm not sure even the SSM at Subaru can tell which one is bad? (at least not for less than the minimum typical hook up charge of $50) You'll likely end up having to play "wack-a-mole" to figure out which one it is and replace one at a time until the light goes out if you want to replace it.

 

As was mentioned, if the light comes on and just stays on, it's a pressure issue. Over inflation will cause this as will under-inflation.

 

FWIW, My Subaru dealer told me I had two dead batteries in the sensor's. He may have told me which ones, but at that point, I didn't care, the black tape has worked fine.

 

Went I put the other set of OEM Spec B wheels on with snow tires, I used to put a piece of black tape over the light, so to me, the black tape is not a big issue.

[08SpecB_DE]

This...

 

The sensor batteries last about 5-7 years. I just replaced two this year on my 2008. I used the Schrader EZ sensor and cloned the new one from the old one.

 

Unless the battery in the TPMS sensor has completely failed, it's a PITA to figure out which one it is because of the lack of battery level feedback from the sensor to most TPMS tools. Typically, there is enough power left in the battery to tell the tool it's good, but not enough to keep the TPMS light on the dash out. I'm not sure even the SSM at Subaru can tell which one is bad? (at least not for less than the minimum typical hook up charge of $50) You'll likely end up having to play "wack-a-mole" to figure out which one it is and replace one at a time until the light goes out if you want to replace it.

 

As was mentioned, if the light comes on and just stays on, it's a pressure issue. Over inflation will cause this as will under-inflation.

 

A scan tool should show low battery. I can usually tell which one is going bad by how long it takes the tpms tool to pick up the sensor.

 

FWIW, big brother made it a law that shops can not do tire work on a car that has tpms issues. If you get an oil change or something it doesn't matter but if you have a bad sensor and they replace your tires and do not address the tpms fault, they can get fined heavily because it is deemed a safety issue. Have not heard of it happening to anyone but if I was the owner of the shop, I'd rather be safe than sorry. IIRC, the fine is $10,000.

[CapnJack]

A scan tool should show low battery. I can usually tell which one is going bad by how long it takes the tpms tool to pick up the sensor.

 

 

That was my hope, however my scan tool nor the tire shop tool did. The battery level just said N/A on all four tires. On other vehicles, it gives a percentage. I figured Subaru was out to make another buck by having to replace all four. I ended up replacing the two front TPMS sensors and my problem went away.

(I hate diagnosis by throwing parts at things.)