Tire Pressure

[davidfkon]

Anyone know how the stems monitor pressure?
Does anything (other then a presumed reset) need to be done when putting on new rubber?

 

[JackMac]

Anyone know how the stems monitor pressure?

TPMS explained: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=44&

Does anything (other then a presumed reset) need to be done when putting on new rubber?

I assume you have a tire shop mounting the new tire(s), so they should take care of it.

 

[davidfkon]

thanks . . . any hints to keep them from messing-up the LR3 suspension when they lift it?

TPMS explained: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=44&



I assume you have a tire shop mounting the new tire, so they should take care of it.

 

[umbertob]

The TPMS module inside the car requests information to the sensors via a low frequency signal through hard wired antennas/initiators located inside each wheel well every few seconds. The wheel sensors (attached to the valve stems) respond by collecting and wirelessly sending to the module coded data inclusive of sensor ID, air temperature, air pressure and acceleration data. The TPMS module compares the received data with the factory numbers stored in the module and triggers tire pressure warnings in the instrument cluster accordingly if it detects a discrepancy. In theory you don't need to reset anything when replacing tires, as long as the inflation pressure is within the factory recommended range. Even if you change position of the tire sensors - move the wheel sensor from front left wheel to rear right for example - or use new sensors, the TPMS module should "learn" their new ID / position after a few minutes of rolling, without throwing fault codes. The exception is the spare wheel, if it's monitored (compact spares aren't.)

 

[JackMac]

thanks . . . any hints to keep them from messing-up the LR3 suspension when they lift it?

Yes, leave the suspension in standard height mode. Make sure that they lift at the correct jackpoints, avoid the air compressor.

When the vehicle comes down off the lift, it may go into super-extended mode (or whatever it is called). You will need to lower it back to normal ride height using the EAS toggle switch on the console.

Should be simple enough. Could be worse, right?

 

[davidfkon]

hehehe something to look forward to! Good Pic!!

 

[umbertob]

Yes, leave the suspension in standard height mode. Make sure that they lift at the correct jackpoints

My manual recommends putting the car in off-road height before jacking or lifting it. I don't know why... Probably because you don't need to work the jack as much to get the wheels off the ground if you start from off-road height aqs opposed to standard. Or it could be that, since after coming down from the lift the car will most likely be in super-extended mode, the EAS module might think it "missed" a step to get there and throw a fault code (which should clear anyway once you lower the car back to normal height using the lever.) I don''t think it makes any difference in the end, but to avoid problems I would just follow the manual directions and put it in off-road height before the tire shop lifts it.

 

[JackMac]

Good point, umbertob, that makes sense.

Just don't put it into access mode, like the kid at my local shop did last time. He thought he was "locking" the suspension.

After coming back down from the lift, the front suspension was all of the way down, and rear was all of the way up. Could not raise or lower using the EAS switch, and had to drive up to speed to force a reset.

 

[techboydino]

I swapped tires a few times and had no issues. I believe you can even replace the needles in the valve stems too with no problems. When I put the truck on the lift I keep it in standard mode . When it drops it will be in super-extended and will have to just be dropped back down. I wish their was a user accessible maintenace lock mode but I guess we cant have everything.

In short, like others stated changing the tires is really no different than other vehicles, just make sure the garage you take it to is aware of the TPMS, otherwise you could shear the sensor off the wheel when you are dismounting the rubber.

 

[davidfkon]

I was told that if the tail gate is open when the rig gets lifted, it does not go into super-extended mode . . .