Calibrating Tire Pressure Sensors??

[Wisdom]

Is there any way to calibrate the tire pressure sensors on a 2004 C5? Last Sunday I topped off the air pressure on each tire to 32 lbs using an inexpensive mechanical pencil-type tire guage. I was surprised to see that the tire sensors show variances of up to 3 lbs between the tires, even though the mechanical guage was measuring 32 lbs when the air was put in. Is there a built-in calibration routine that I need to run, or are the sensors simply not that accurate?

- Wisdom

 

[MAC5]

I'm not aware of any recalibration routine. The only routine you can do with the sensors is the "relearn", that reprograms the DIC to recognize each wheel in its correct sequence. I'd pitch the "inexpensive pencil tire gauge" and either borrow or buy a high quality digital or mechanical one. I've had my 98 since new and most of the time the fluctuation between my manual readings and the gauges has been 0-2lbs.

 

[rsimoes]

They are supposed to be +- 1 PSI. Maybe the pencil gauage is at fault here. . . Also, if the tires are at different temperatures, they will at at different pressures. Check them all in the morning, before the first drive of the day and before the sun hits the tires, if your car is outside. If it is inside, make sure there is not a heat source near any of the tires. . .

 

[Wisdom]

hmmmm....I'll check them in the morning before I drive then. But I would think that if the mechanical device showed 32 lbs on each tire, then the sensors would at least show a similar pressure for each tire - within the +/- spec noted by rsimoes.

Any idea what the sensor relearning exercise does? I came across it in a different thread/forum earlier this evening. Does the relearning exercise just enable the DIC to map a tire sensor to a wheel location? Being very new to the car, I'm still under the learning curve with many of the discussions on these forums. But I'm learning fast! Or at least people are pulling me along!

- Wisdom

 

[MAC5]

That is correct, the relearn procedures just confirms that the reporting sensors are reporting and in correct sequence. I believe at least for the older sensors, 97-00, that the sequence is LF, RF, RR, LR.

 

[rsimoes]

I don't think the relearn will help. it's just relearning the RF frequency for each tire. I would get a quality pressure guage and check it against the sensors. But here are the relearn procedures:


http://www.corvettecavalry.com/techtips.html#tpms

 

[Wisdom]

The sensor measurements yesterday morning (after the car sat in the garage all night) did differ from the mechanical guage on a couple of sensors. I'll get a digital pressure guage this week and check them against that. I'm beginning to think that the sensors are only accurate to something within 5-10%. That may be all that matters.

- Wisdom