TPMS sensor

[Logan00]

I have searched but have been unable to find an answer to my question. I have a 2008 M35x and one of my TPMS sensors is not working. The caution light displays on the dash and I have driven the car for over 100 miles since it stayed on with no luck. It is only affecting 1 tire as the rest of the sensors work properly.

How to I know if I need to replace my current sensor, change the battery (saw that in a previous post) or bring it to the dealer?

Thanks

[frapjap]

Thats a heck of a question man.
I'd suggest starting with the FSM and the sensor. But then again, I hate, hate, hate just blindly throwing money at a problem that isn't confirmed.
If you haven't used it yet, we have Factory Service Manuals available free to members. Take a peek at the link in my signature and find the FSM for your car and you'll have all the info you'll ever need to make the repair and try to diagnose it for yourself while help is on the way.

[kmiles]

The TPMS sensor has a built-in battery, which is not replaceable. I had the same problem and had the TPMS sensor replaced at Discount Tire the last time they rotated my tires. It cost me $65 including installation and the part and now I no longer have the blinking light on the dash.

[Logan00]

Thanks guys, I should be getting my tires rotated soon so I will have them check the sensor at the same time.