Mechanics

TIRE PRESSURE MONITORING SYSTEM

2007 Toyota Camry

Tires and Wheels problem
2007 Toyota Camry 4 cyl Front Wheel Drive Automatic 27000 miles

My tire pressure light keeps coming on. No tires are below specified pressure. Dealer tells me that the indicator light comes on when differential pressure is noted not low pressure as stated in the owners manual. The pressures are within 2 psi at all times. Dealer also stated that the pressures are read and it is not linked to the ABS that looks at tire revolutions. Is the system working correctly? Is the dealer correct? Is the tolerance on monitoring system too tight?
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Hwellens
January 12, 2009.



Monitor tire pressure only
check on the driver door jam for the correct tire pressure for your car
adjust as needed

TIRE PRESSURE MONITOR (TPM) SYSTEM

The Tire Pressure Monitor (TPM) system is designed to provide warning when tire inflation pressure of one or more tires (including spare tire) is low.
A tire pressure monitor valve sub-assembly containing a tire pressure sensor/transmitter is installed in each tire/wheel assembly. The sensor measures the internal tire pressure and temperature.
These measured values and transmitter ID(s) are transmitted to the tire pressure monitor receiver assembly on the body via radio waves.
This data is then sent to the tire pressure monitor ECU from the tire pressure monitor receiver.
If the transmitter ID has been previously registered, the ECU compares the measured air pressure value and the standard value.
When the value is less than the standard value registered in the tire pressure monitor ECU, the tire pressure warning light on the instrument cluster will turn on.
To accommodate the need to change the standard values recorded in the ECU when changes in operating conditions occur, or a different type of tire is installed, a tire pressure warning reset switch is provided. When activated, the current pressure values are stored in the ECU as the new standard values.

TIRE PRESSURE MONITOR WARNING LIGHT

When the tire pressure warning light does not go off, or when it comes on during driving, check tire pressure (including spare tire) and adjust as necessary. The warning light should go out within a few minutes.
If the warning light is still on even though the tire pressure is correctly adjusted, the tire could be punctured. Repair as necessary.
If the warning light is still on or blinks, after investigating all of the above, there is a malfunction in the TPM system. See appropriate manufacturer service information.
Under the following conditions, the system may not function properly: Facilities or devices that use similar radio wave frequencies are located in the vicinity of the vehicle.
A radio device of similar frequency is used near the vehicle.
A large amount of snow or ice is stuck to the vehicle, especially around the wheels or wheel housings.
A tire without a tire pressure sensor is used.
Snow tires or tire chains are used.
The battery of the sensor has been depleted.
Wheels other than manufacturer factory wheels are used. If any wheels other than those specified are used, the system may not function properly because radio wave transmission from the tire pressure sensors may be affected.
Radio transmission from the air pressure sensor installed on the spare tire is not being received. This may be rectified by changing the orientation of the spare.
Depending on the tire type, the system may not function properly even though the specified wheels are used.

BMRFIXIT
Jan 13, 2009.