BENDIX BW2809 manual Introduction, Testing Tire Sensors

Introduction

The tire pressure monitoring system consists of a tire pressure sensor inside the tire that transmits a radio frequency (RF) signal containing a unique identification number (ID #), actual tire pressure, and sensor battery condition to a module in the vehicle. The vehicle module receives and interprets the RF signal from the sensor and warns the driver of low tire pressure.

Note: Early systems used one of two types of tire sensors: a tire sensor with an orange cover that had a battery-saving “stationary mode”; and an “always on” tire sensor with a yellow cover. Later systems exclusively use the yellow “always on” tire sensor.

It is important that the vehicle module knows exactly where each sensor is located on the vehicle so it can indicate to the driver which tire has incorrect pressure. Note: Whenever the tires are serviced or rotated, it is important that the vehicle module relearns the current position of each tire pressure sensor and tire and wheel assembly. (See "Walk-Around Learn" on page 11.)

The tire pressure sensor responds with a signal for a period of time once the "activate" button is pressed on the hand Tool.

The main menu of the Tool identifies three functions — the Initiate, Setup and Learn modes respectively.

Testing Tire Sensors

The sensor test procedure is used to verify that the sensors can transmit valid data after they have been activated with a low frequency (LF) transmission from the Tool. Refer to the vehicle service manual for further diagnostic information. During this procedure, the Tool receives sensor transmissions and displays the transmission data on the screen.

1.The antenna of the Tool should be placed against the sidewall above the wheel rim at the valve stem location. Holding it too close to the rim (while initiating an inner tire sensor on a dual tire configuration, may cause the outer tire sensor to be initiated as well).

2.Press and release the Initiate button on the Tool. The circling symbol indicates the Tool is scanning for the sensor's transmission.

3.With the Tool in position, observe the screen and wait 3-5 seconds for the sensor's transmission to be received. The screen should display an eight-digit ID number, tire pressure within 2 psi of actual tire pressure, and the tire’s temperature.

4.Repeat the steps above for the remaining sensors to verify all sensors are operating properly.

NOTE: Sensor transmission data displayed on the Tool screen is erased each time the Initiate or Learn functions are selected.

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