Jaguar X-Type Sedan and Estate (Wagon). Manual - part 46
Tire Pressure Monitoring System
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 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 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 tend 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
malfunction warning.
The system comprises a TPMS module, a RF antenna, 4 initiators and 4 tire pressure sensors (the space saver spare wheel is not fitted with
a sensor).
The TPMS module is located under the Right-Hand (RH) side of the rear seat. The RF antenna is located behind the rear bumper. The front
initiators are positioned at the front of the wheel arches. The rear initiators are positioned at the rear of the rear wheel arches.
The 4 initiators are hardwired 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 MHz RF signals are detected by the RF antenna 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 high speed Controller Area Network (CAN) bus to provide the driver with
appropriate warnings. The TPMS module also indicates status or failure of the TPMS or components.
Tire Location and Identification
The TPMS can identify the position of the wheels on the vehicle and assign a received tire pressure sensor identification to a specific
position on the vehicle, for example FL (front left), FR (front right), RL (rear left) and RR (rear right). This feature is required because of the
different pressure targets and threshold between the front and rear tires.
The wheel location is performed automatically by the TPMS module using an 'auto-location' function. This function is fully automatic and
requires no input from the driver. The TPMS module automatically re-learns the position of the wheels on the vehicle if the tire pressure
sensors are replaced or the wheel positions on the vehicle are changed.
The TPMS software can automatically detect, under all operating conditions, the following:
one or more new tire pressure sensors have been fitted
one or more tire pressure sensors have stopped transmitting
reject identifications from tire pressure sensors which do not belong to the vehicle
two 'running' wheels on the vehicle have changed positions.
If a new tire pressure sensor is fitted on any 'running' wheel, the module can learn the new sensor identification automatically when the
vehicle is driven for more than 15 minutes at a speed of more than 20 km/h (12.5 mph).
The tire learn and location process is ready to commence when the vehicle has been stationary or traveling at less than 12 mph (20 km/h)
for 15 minutes. This is known as 'parking mode'. The learn/locate process requires the vehicle to be driven at speeds of more than 20 km/h
(12.5 mph) for 15 minutes. If the vehicle speed reduces to below 20 km/h (12.5 mph), the learn process timer is suspended until the vehicle
speed increases to more than 20 km/h (12.5 mph), after which time the timer is resumed. If the vehicle speed remains below 20 km/h (12.5
mph) for more than 15 minutes, the timer is set to zero and process starts again.
If the tire pressure sensors fitted to the running wheels vehicle are changed, the module can learn the new sensor identifications
automatically. The learn function requires no manual intervention by the driver.
Initiator