TPMS question

[Doublecardan]

I have a 04 Liberty Renegade that after 8 model years, the batteries in the Tire sensors are starting to wear out especially here in the minus 20 to 30 days and nights. I ordered 5 new ones from Rockauto and no problems there but when I got them, I wondered if they were already transmitting a signal and how much life was left in them. Can you imagine a whole warehouse with transmitting tire signals. There was not a date on the box, but maybe the code would shed some light on it.
cheers

 

[hyde]

Interesting, never thought about the battery in those suckers. I didn't think they would be transmitting unless there was some pressure on them. Wouldn't you think so? When the tire is flat it is 0 (no pressure/no signal)..

 

[Doublecardan]

thats a good point, when i installed them, the evic is reading 0 on all four corners and is flashing. it appears the 04 is different from the 05 and up in that the later years use some sort of transponders in the wheelwells, 3 of them. It appears that to wake them up and start transmitting they have to be going a certain speed, 25 mph. when it stops raining here I am going to see what happens.

 

[hyde]

That's used to detect swaps. Good Luck, I have no idea about 04/05 difference for TPMS.

 

[tjkj2002]

The TPMS sensors are transmitting the PSI they are reading(which is always 3-4psi lower then actual) no matter what until it gets broken or the battery dies.Once that battery is installed when they make them it is transmitting.When putting new ones on you need to program them so your vehicle will read there coded freqs.

 

[Doublecardan]

Thanks for the good advice, that's exactly what I did, it was easier than i thought, I hope I will be good for another 7 years. By then the jeep will just broken in.