Join Date: Oct 2004
Location: Lake Jackson, Texas
Mentioned: 3 Post(s)
Tagged: 1 Thread(s)
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Tire Pressure Monitoring System
There has been a lot of discussion (and some mis-information) about the TPMS on our vehicles. I hope this will shed some light on the subjuct.
Each of the four tires on the ground has a pressure sensor in it. There is no sensor in the spare; the system can "read" only four sensors. This sensor is built into the tire valve stem. Each sensor sends a pressure signal by radio to a receiver in the dash, the same one that receives the keyless entry system signal. These signals are then sent the the Body Control Module (BCM). The BCM controls the low tire pressure warning light and buzzer.
If the TPMS system receives a low pressure signal from one or more wheel sensors the light and buzzer will go off. If the system is not receiving 4 signals from the sensors it indicates a system problem and only the light goes on.
Contrary to what others have posted, you can't turn the system off.
In fact, there are Federal laws concerning this:
Congress passed the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in the fall of 2000. This requires a warning system to indicate under inflated tires.
Automakers had to be 70% compliant by September 1, 2006 and 100% compliant by September 1, 2007. (Section 13 of the TREAD Act).
By Federal law (49 U.S.C. 30122(b) the TPMS system can't be bypassed:
"A manufacturer, distributor, dealer, or motor vehicle repair business may no knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard prescribed under this chapter..."
It is not against this law to remove sensors yourself, but a shop could refuse to work on any vehicle that violates this law.
Many of the larger tire stores now stock the sensors and repair parts. The car makers seem to be setting a standard for the sensors, so most will interchange. The tire stores also have the programmer to activate the sensors.
The TPMS is a good thing. It could save you a wheel, tire, prevent an accident or even save your life. I urge everyone to keep the system intact. If you get new wheels, install sensors in them.
If any sensor other than the ones that came on the vehicle are used, they must be programmed to your vehicle. You can move sensors from your original wheels to new wheels without having to reprogram them.
Also, it is not necessary to reprogram sensors when the four tires on the ground are rotated. You don't use the spare in the rotation since there is no sensor in it.
I hope this answers questions about the TPMS.