Tire pressure sensors/flat tire

[golfrbob2]

I have had my 2003 M45 for about 2 months. The tire sensors have never worked. After about 35 miles, I get a tire pressure warning, but whenever I check the pressures, it just shows up as **. Nonetheless, after the 35 miles, I get the warning and the light on the instrument panel comes on.

I would like to know if anyone knows what the deal is with that....

But the new problem is even more annoying. This morning, the TPMS told me that my right tire was flat. It's not. And when it flashes on the screen that it is flat, all tire pressures still read **. I got to work, turned the car off and turned it back on about half an hour later and again, it tells me the right tire is flat.

Any ideas???

Thanks

[szh]

What pressure (using an external gauge) are your tires set at?

With the typical tires that are available for the M45, you should be running about 36psi. If the external measurement shows this for all four tires, it looks like your TPMS is faulty, or needs a battery change or something.

Z

[lswaidz]

I've seen that error before on cars with bad body control modules and/or ECM's. Take you car into a dealer and have them take a look at it. That could turn into a potentially fatal problem. Get it taken care of ASAP!

[Chi-town M45]

It could be your car has the full size spare on one of the tires which will cause all 4 tires to not register. The spare does not have a sensor in it and the system needs all 4 tires to have the sensors in order for it to work. If you have a good spare try putting that on and see if that does the trick.

[M45-Zero260]

If this was the case, wouldn't the tire w/sensor in the trunk still send an RF signal to the computer with it's psi indication?

The reason why I'm asking is, my Father's '07 Mustang has the TPMS, and when he put different wheels/tires on it after he got it, he found that it gave him an annoying warning icon on his instrument panel, because there was no signal telling the computer what the psi was.

The forum he is on told him to take all 4 sensors out of the origional wheels and fabricate a small PVC pipe with a valve stem - put the sensors in there, screw on the end cap, and pressurize the pipe to 33 psi and mount in the trunk somewhere out of site to "fool" the computer. (I know this totally defeates the purpose of having TPMS, but I thought it was an interesting temporary alternative, and he has got through over 40 years of driving cars without TPMS).

Anyway, my '03 started acting funny on this a few months ago, giving me an over-pressure warning, and now no matter how far I drive, I get no indication at all anymore. If 1 battery can cause all 4 to not give a signal, then I will take to my local tire shop and have them un-mount all 4 tires and put fresh lithium batteries in.

Last year when I had a whole new set of Michelin Pilots put on, I remember the mechanic telling me that for some reason, the batteries do not last more than 4 years for some reason.

[lfj2025]

I don't think that will work with our system. When you start the car all you get is ** until you reach around 35 mph.

Also, my spare came with a sensor , so I have all five tires with sensors. The system only reads the ones that are spinning.

[M45-Zero260]

Ah....I didn't know that. That explains why it always took a while for them to start registering when they were working. Thanks for the info! I will definitely get mine looked at soon to see if it's just a battery issue.