Tire Pressure Monitor
01-05-2009, 05:23 PM
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My Ride: '06 550i
'84 Nissan S12 Turbo
How much psi do the tires have to lose for the monitor system to pick up? I took out the "above 100mph" pressure down to the "under 100mph" pressure, and I didn't get any kind of warning when I drove it
01-05-2009, 05:30 PM
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Originally Posted by ktlocklear' post='760268' date='Jan 5 2009, 06:23 PM
How much psi do the tires have to lose for the monitor system to pick up? I took out the "above 100mph" pressure down to the "under 100mph" pressure, and I didn't get any kind of warning when I drove it
The old TPM system measures "tire pressure" using rotation speed in relation to other wheels so if you decrease the pressure on all 4 tires it wont think there anything wrong.
01-05-2009, 06:42 PM
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Originally Posted by ktlocklear' post='760268' date='Jan 5 2009, 08:23 PM
How much psi do the tires have to lose for the monitor system to pick up? I took out the "above 100mph" pressure down to the "under 100mph" pressure, and I didn't get any kind of warning when I drove it
01-06-2009, 12:29 AM
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My Ride: 05 530i
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85 VW GTI
My right front had 20psi and no sensor warning. In fact the only time there was a warning was when i bought the car and filled up the tires with air. One tire had 15psi.
01-06-2009, 06:55 AM
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Originally Posted by ktlocklear' post='760268' date='Jan 5 2009, 09:23 PM
How much psi do the tires have to lose for the monitor system to pick up?
01-06-2009, 07:03 AM
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Originally Posted by p291cxb' post='760648' date='Jan 6 2009, 07:55 AM
Looks like the TPM system will give you a warning (yellow) if pressure drop by 4 psi, so about 12%. I monitor my tirea on a monthly basis, but received a warning when the temperature dropped significantly, from +10 C to -26 C, a few weeks ago
Your system is different. it actually has a sensor in the wheel to detect actual pressure not just using wheel rotational speed.
01-06-2009, 07:05 AM
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Originally Posted by einstein57' post='760512' date='Jan 6 2009, 01:29 AM
My right front had 20psi and no sensor warning. In fact the only time there was a warning was when i bought the car and filled up the tires with air. One tire had 15psi.
Was the 20psi and 15psi on the same axle? IE Both Front tires? The old system is only there to warn the driver of a significant pressure lost like running over a nail. Its still the drivers responsibility to check the tire pressure regularly.
01-06-2009, 07:22 AM
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Originally Posted by einstein57' post='760512' date='Jan 6 2009, 04:29 AM
My right front had 20psi and no sensor warning. In fact the only time there was a warning was when i bought the car and filled up the tires with air. One tire had 15psi.
did you reset the monitor?
01-06-2009, 07:28 AM
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I actually had my TPM go off when I started my 550 a few days ago. I didn't drive the car for a few days and right away, even before driving, the sensor notified me about my rear driver side tire pressure. The psi was 30 on a cold start and the rest of the tires including fronts were at 40. Not sure why I lost pressure, but over the last 4 days, it has maintained pressure of 40 all around.