BMW Mini models from 2001 onwards have been fitted with Tyre pressure monitoring systems, referred to by BMW as RPA systems. Unlike other Tyre pressure monitoring systems, the BMW Mini system does not directly measure the tyre pressure in each wheel, as with other manufacturers using Tyre pressure monitoring systems.

Instead, on the BMW RPA system, the Tyre pressure monitoring is carried out by the RPA system measuring the speed of each of the vehicle’s wheels as the vehicle is being driven. A l oss of pressure in a tyre will reduce the rolling circumference of the wheel , and therefore the wheel with lower tyre pressure will be seen by the RPA system as turning at a different speed to the other wheels .

The RPA tyre pressure monitoring system uses the vehicle’s ABS wheel speed sensor s to determine the rotating speed of each of the wheels . The information on the wheel speeds is then passed to the RPA control module via the Dynamic Stability Control ( DSC) module .

If the RPA tyre pressure monitoring system detects a loss of tyre pressure on one or more of the vehicle’s wheels, an RPA indicator warning light will turn “ON” in the instrument cluster. The RPA warning light is used to indicate 3 different conditions of RPA faults on the vehicle:

1. RPA warning light flashing = Vehicle may have flat tyre - Check tyre pressures

2. RPA warning light “ON” continuously = RPA s ystem Mlfunction - Check RPA tyre pressure system

3. RPA warning light remains “ON” for 16 seconds (from ignition switched “ON” / engine running) = The RPA tyre pressure system needs calibrating

CALIBRATING (RESETTING) OF THE RPA TYRE PRESSURE MONITORING SYSTEM

If the RPA warning light remains turned “ON” for 16 seconds after switching the ignition “ON” / starting the engine, this indicates that the RPA system has previously detected a loss of tyre pressure, and therefore changes in the wheel speeds, which has been calculated by the RPA control module as likely to be caused by either changing wheel positions on the vehicle or checking / adjusting the tyre pressures on the vehicle.

In this condition, the RPA is indicating to the driver that the RPA system requires a calibration (reset) for the suspected changes in tyre pressures on the vehicle. Once the correct tyre pressure s for each wheel have been set by either the driver or garage, the RPA system can then be calibrated (reset) .

Calibrating / resetting procedure

Note. The following c alibration procedure must be performed every time the air pressure in the tyres has been changed or when the position of a wheel has been changed on the vehicle .

The driver or garage can carry out a calibrat ion (resetting) of the RPA tyre pressure monitoring system by pushing the RPA reset button for approximately 6 seconds with either the ignition switched “ON” or the engine running at normal idle speed. The RPA reset button is usually located directly under the hand brake lever .

After the RPA reset button has been operated, the RPA tyre pressure monitoring control module will automatically relearn the vehicle’s tyre pressure reference status. Depending on owner driving style s and road condition s, this can take from 45 min utes up to 7 hours for the RPA tyre pressure monitoring system to correctly determine and diagnose pressure changes for each wheel.

Note. A fter 10 minutes of the vehicle being driven after the RPA reset button has been pressed , the RPA tyre monitoring control module can diagnose if any tyre pressures ha ve changed to 50% or more inflation loss .