Description And Operation: Overview: Notes

The TPMS is a driver assistance system which assists the driver to maintain the tire pressures at the optimum level. The TPMS is a standard fitment on North American Specification (NAS) vehicles and an optional fitment in other markets. The TPMS system has the following benefits:

Improve fuel consumption
Maintain ride and handling characteristics
Reduce the risk of rapid tire deflation - which may be caused by under inflated tires
Comply with legislation requirements in relevant markets.

CAUTION: The TPMS is not intended as a replacement for regular tire pressure and tire condition checks and should be considered as additional to good tire maintenance practices.

The TPMS measures the pressure in each of the tires on the vehicle (the space saver spare wheel is not monitored) and issues warnings to the driver if any of the pressures deviate from defined tolerances.

NOTE: During a 'blow-out' a very rapid reduction in pressure is experienced. The system is not intended to warn the driver of a 'blow-out', since it is not possible to give the driver sufficient warning that such an event is occurring, due to its short duration. The design of the TPMS is to assist the driver in keeping the tires at the correct pressure, which will assist to reduce the likelihood of a tire 'blow-out' occurring.

The controlling software for the TPMS is located within a TPMS module. The software detects the following:

the tire pressure is below the recommended low pressure value - under inflated tire
the position of the tire on the vehicle.

The system comprises a TPMS module, a Radio Frequency (RF) receiver, 4 initiators and 4 tire pressure sensors (the space saver spare wheel is not fitted with a sensor).

The TPMS module is located behind the Left Hand (LH) rear passenger seat, behind the Auxiliary Junction Box (AJB) and the TPMS RF receiver is located on the AJB mounting bracket. The front initiators are positioned at the front of the wheel arches, behind the fender splash shields. The rear initiators are positioned at the rear of the rear wheel arches, behind the fender splash shields.

The 4 initiators are hard wired to the TPMS module. The initiators transmit 125 KHz Low Frequency (LF) signals to the tire pressure sensors which respond by modifying the mode status within the RF transmission. The 315 or 433 MHz RF signals are detected by the RF receiver which is connected directly to the TPMS module. The received RF signals from the tire pressure sensors are passed to the TPMS module and contain identification, pressure, temperature and acceleration information for each wheel and tire.

The TPMS module communicates with the instrument cluster via the medium speed CAN bus to provide the driver with appropriate warnings. The TPMS module also indicates status or failure of the TPMS or components.