[Oldslowandugly]

While working on the '08 I rotated the tires. Normally that triggers a TPMS light on the dash and I have to do the 'learn' sequence for all the tires. This time- nothing. I know that the '08 is not self-learning. I wonder why the TPMS monitor is happy with the new tire positions?

 

[1966tbird]

The TPMS computer sees and recognizes all 4 wheel sensors, Mind you, it does not know where they are now.
To test, Simply deflate one and check the driver information display and see which tire the TPMS displays as low.

I assume you have air at your shop.
Rince and repeat to your satisfaction…..or force a relearn ro confirm LF = LF. …RF=RF…

 

[Oldslowandugly]

Yeah, but it identifies each sensor by the part number and serial number. Even according to the FSM if you move a wheel the computer gets confused and sets the code. I know because I have done it before and the TPMS light came on right away. I don't bother inflating/deflating- I have the AUTEL scan tool that activates the sensor so the computer can sense it. The procedure is a combination of using the car's computer to run the relearn sequence where you follow the horn beeps and light flashes from wheel to wheel. But instead of messing with the tire pressure the scan tool activates the sensor and you are done in no time. But the computer is either drunk from the night before or doesn't care this time?!?

 

[1966tbird]

I’m betting your sensors are broadcasting well enough the tpms receiver is getting a signal for the LF and knows that sensor. If you removed the wheel and rolled it over to the RR, the tpms receiver would still see the wheels sensor and think all is well in the world….according the the tpms receiver.

just try it……start by reading the pressure of the 4 tires as they are now….then deflate say 3-5 psi from say the LF and see what the information display says what wheel is lower than the other 3

 

[Oldslowandugly]

So you are saying the monitor can read the sensors and still 'think' they are where they belong? Hmmmmm I thought they were smarter than that. Maybe I give these cars too much credit? On my Jeep if I sneeze while gassing up it sets an EVAP code!

 

[1966tbird]

And yes I agree with you that it logs each wheel sensor….,but you must tell the tpms receiver which wheel the sensor is mounted to. Then the tpms receiver/computer stores the pressure in its data location for the wheel location you were workin with. Now that the sensor is logged, it no longer needs to be bolted to the car, just as long as it can receive a valid signal,,,,the tpms system is happy

 

[1966tbird]

Lol…that’s a Jeep for you…..

or any other car with an attitude.

 

[Oldslowandugly]

Now that the sensor is logged, it no longer needs to be bolted to the car, just as long as it can receive a valid signal,,,,the tpms system is happy

Ok that is not what I thought. But since it is happy, I guess you are right. Always learning.....

 

[1966tbird]

Just give it a try…..I would love that GM put a tdr in the tpms….
TDR=. Time domain reflectometer

 

[1966tbird]

Any update?

 

[Oldslowandugly]

No, my grandson is using it for school. It doesn't stand still long enough. So I would have to run alongside to service it.