The TPMS Tyre Pressure Monitoring System checks the pressure and temperature of the tyres at all times sending the necessary information via the CAN.

In particular, it activates signalling in the instrument panel if the inflation pressure is too low in one or more of the tyres or if there is a puncture.The system comprises a control unit inside the passenger compartment (in the luggage compartment, right hand side) and four transmission sensors located inside the tyre on the wheel rim which send signals to four receiver aerials.

The aerials acquire information on the status of the four tyres via radio signals. They then communicate with the tyre pressure control unit, which communicates with the Body Computer via the CAN.

At key-on, the control unit conducts an initial check: when the vehicle moves, the sensors measure the pressure and then make a transmission to indicate the initial status.The receiver receives this transmission from all the sensors within 5 seconds so that it can check tyre function.

Two intervention thresholds are identified that are stored inside the receiver. The first (defined as CHECK) indicates that one or more tyres are at a pressure slightly lower than optimum pressure and the user should therefore check and restore the correct value.The second threshold (defined as WARNING) is set to indicate a constant or sudden pressure loss due to a puncture in one or more tyres.

For more details:

  See descriptions 4450 HUBS AND WHEELS 

The control unit supply lines are protected by dedicated fuses in the Body Computer.

Control unit M047 is supplied at pin 1 directly from the battery from a line protected by fuse F36 of Body Computer M001.

The ignition-operated power supply (INT) reaches pin 16 via the line protected by fuse F49 of the Body Computer M001.

The control unit is earthed at pin 10.

The CAN line connected to the Body Computer M001 leaves from pins 8 and 9 of M047.

The Body Computer M001 - connector A - receives a direct power supply from the battery through the line protected by maxi fuse F01 of the engine compartment junction unit B001.

The Body Computer M001 receives an ignition-operated power supply (INT) at pin 11 of connector E.

Pin 9 of connector E of M001 provides the Body Computer with a reference earth.

The four receivers for the sensors P012 receive a 5 V power supply from pin 2 of M047 and a reference earth from pins 12, 13 and 15; they send a pressure signal to pins 3, 4, 5 and 6 of M047.