Tire Damage Indicator (RPA)

Operating principle: The tire pressure monitor checks the air pressure in all four tires while the vehicle is being driven.

The system gives a signal when the pressure in one of the tires drops significantly compared with the other wheels.

Pressure loss is determined as follows: the system monitors and compares the rotational speeds of the individual wheels. If the speed of one wheel differs, the system signals damage to its tire.

Prerequisite for operation: For the system to operate reliably, it must be initialized when the air pressure in all tires is correct.

Physical limits of system operation

The tire pressure monitor cannot warn of a sudden severe tire failure caused by external influences. It also does not respond to a natural, uniform pressure loss in all four tires.

In the following situations, the system may respond late or incorrectly:

► when driving on snowy or slippery roads;
► when driving in a sporty manner (wheel spin on driven wheels, high lateral acceleration).
► When driving with snow chains, the system may give a false warning or, conversely, fail to detect a pressure loss.
► The tire damage indicator does not function when you are driving on a compact spare wheel.

System Initialization

Perform initialization immediately after adjusting tire pressure or replacing a tire or wheel.

To do this, drive several kilometers.

1. Start the engine, but do not move the vehicle.
2. Press and hold the button until the indicator lamp in the instrument cluster lights up yellow for a few seconds.
3. Start driving.

After a few minutes, the RPA system will be able to detect tire damage.

Do not initialize the system while snow chains are fitted or a compact spare wheel is installed.

Tire Damage Message

The warning lamp lights up red and an audible signal sounds: a tire puncture or excessive pressure loss in one of the tires.

1. Reduce speed and stop in a safe place, avoiding abrupt steering or braking inputs.
2. Determine which wheel is damaged.

If you cannot determine which wheel is damaged, contact a BMW service center.

3. Replace the damaged wheel, see "Changing a Wheel".

Malfunctions

The warning lamp lights up yellow: the tire damage indicator is experiencing interference or is malfunctioning. Have the system checked at a BMW service center as soon as possible.