GMCTech,
Thanks for the offer of the directions. The fine techs at my dealership printed it out for me, and it works. I have regurgitated it below.
Eggert, the sensor is part of the valve stem. A little blue plastic encapsulated module ( growth )
at the end of the stem, inside the rim. The stem is held in with a 13mm nut now. The sensor can't weigh more than a 1/2 ounce. Pretty cool little bugger.
Yes, Firestone knocked out one of the tire sensors while mounting the tire. GMC provided a new one for $71 including tax. Not a nice price, oh well. The Firestone/Bridgestone dealer paid me for it in cash. I like these guys....
Here is the procedure for putting the system into 'Tire Pressure Sensor Learn Mode'.
Basically each tire has a separate transmitter that is known to the BCM, and if you change its position by rotating tires , they all have to be 'resynced' so the BCM knows which tire is where. This will need to be redone after rotating tires too. Nice.
So....
Important: Before proceeding, ensure that no other sensor learn procedures are being performed, or that tires pressures are not being adjusted on a TPM vehicle within close proximity. ( I swear, this is in the procedure! )
1. IGN ON / Engine Off
2. Parking Brake ON ( or it won't work!! )
3. Enable the Learn mode by:
a. Turn the exterior lamp switch from OFF to parking lamps 4 times
in 4 seconds, then leave it ON.
b. The horn should double chirp, and the low pressure
indicator on the dash should begin to flash.
NOTE: If the learn mode cannot be entered, make sure it is ENABLED in the PDM ( Passenger Door Module ) ( so... is this where we look to disable this nice feature ? )
4. Starting at the left front tire, increase or decrease the tire
pressure until you get a horn chirp ( BCM is acknowledging the LF
tire sender ) This usually takes 8-10 seconds, maybe less, maybe
up to 30.
5. Repeat this for the other tires, following the sequence of:
RIGHT FRONT
RIGHT REAR
LEFT REAR
6. At this point the BCM should now know which tire is where,
7. Exit the "Learn Mode" by turning off the ignition.
NOTE: The BDM will exit the learn mode if more than 2 mintues passes without a new tire being learned. So hussle out there!!
You can now reinflate to the desired pressure ( check the door sticker ),
then turn the ignition back on, start it up and all should be fine.
The BCM measures pressures in all tires once every 20 seconds. If
there is a difference of more than 1.6 psi from the last reading, the
BCM will set the light.
Fun huh ? The Bridgestone guy must have also switched some rims around.
Hope this helps someone in the future. It needs to be in the owners manual since most of us rotate our own tires ( I would think ).
Gerry-
Norfolk, VA