GF40.15-P-0001TRU Tire Pressure Monitor Function

GF40.15-P-0001TRU Tire pressure monitor function
- with CODE (470) Tire pressure monitor (base)
- with CODE (494) USA version

Component Identification:

General
The tire pressure monitor system assists the driver with the permanent monitoring of the correct tire inflation pressure and thus serves active safety.

The tire inflation pressure and tire temperature are measured in the tire at regular intervals and transmitted to the TPM [RDK] control unit via a high frequency transmission link.

Via the multifunction display (A1p13) in the instrument cluster (A1) the driver is informed about the necessary corrections to the tire inflation pressure and about flat tires.

The TPM system increases safety through prevention
^ A tire burst, triggered by excessive flexing energy and driving quickly with too low tire pressure, is prevented.
^ The driver is requested to check the tire inflation pressure.
^ A warning ensues in good time in the event of a rapid pressure drop (pressure drop more than 0.2 bar/min).
^ Regular checking of tire inflation pressure is simplified.

A sudden tire pressure drop cannot be detected due to the system.

Working life and economy
Tire wear and fuel consumption are reduced by having the correct tire pressure.

The TPM system does not release the driver from a regular manual check of the tire inflation pressure (at least every 14 days). In the process the correct tire inflation pressure must be adjusted by means of the table in the fuel filler flap. The TPM does not warn about an improperly adjusted tire inflation pressure.

The TPM system consists of the following components:
^ Central TPM [RDK] antenna (A2/97)
^ Left front tire pressure monitor sensor (A69/1)
^ Right front tire pressure monitor sensor (A69/2)
^ Left rear tire pressure monitor sensor (A69/3)
^ Rear right tire pressure control wheel sensor (A69/4)
^ TPM [RDK] control unit (N88)
^ Scroll forward/back button (S110s1)
^ Buttons + and - for setting specific functions and volume control (S111s1)

Function
The wheel sensors are attached to the metal valves of the rims, not visible from the outside, and measure the air pressure and tire temperature in the tires.

The signals are received by the central TPM [RDK] antenna and passed on to TPM [RDK] control unit via a discreet line.

While driving the left front TPM [RDK] wheel sensor, right front TPM [RDK] sensor, left rear TPM [RDK] and right rear TPM [RDK] sensor transmit three data messages every 60 seconds. The absolute pressure, the wheel temperature, the acceleration, the ID and status information on manufacturer, frequency, pressure range etc. are transmitted in these data messages. The measuring range of the TPM wheel sensor covers between 0 and 5.5 bar (relative pressure).

The ID serves the detection of the wheels fitted to the vehicle and not the position determination (e.g. front left).

The TPM [RDK] control unit is permanently operational. Each time CAN B is awoken (Controller Area Network bus Class B (interior)) by the starting procedure or ignition "ON", the TPM [RDK] control unit carries out a reinitialization and starts to transmit messages to the instrument cluster.

In the TPM [RDK] control unit the air pressure of each wheel activated and adjusted by the driver is stored as the specified pressure to be monitored.

The data evaluated by the TPM [RDK] control unit in the form of messages relevant to operation and function are displayed in the multifunction display of the instrument cluster.