Tire pressure monitor

General notes

If a tire pressure monitor is installed, the vehicle's wheels have sensors that monitor the tire pressures in all four tires. The tire pressure monitor warns you if the pressure drops in one or more of the tires. The tire pressure monitor only functions if the correct sensors are installed on all wheels.

Information on tire pressures is displayed in the multifunction display. After a few minutes of driving, the current tire pressure of each tire is shown in the Serv. menu of the multifunction display. For further information on displaying this message, refer to the "Checking the tire pressure electronically" section  .

Example: current tire pressure display

Important safety notes

WARNING

Each tire, including the spare (if provided), should be checked at least once a month when cold and inflated to the pressure recommended by the vehicle manufacturer on the Tire and Loading Information placard on the driver's door B-pillar or the tire pressure label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size indicated on the Tire and Loading Information placard or the tire pressure label, you should determine the proper tire pressure for those tires.

As an added safety feature, your vehicle has been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires are significantly underinflated.

Accordingly, when the low tire pressure telltale illuminates, you should stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.

Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability.

Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has not reached the level to trigger illumination of the TPMS low tire pressure telltale.

USA only: Your vehicle has also been equipped with a TPMS malfunction indicator to indicate if the system is not operating properly. The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the warning lamp will flash for approximately a minute and then remain continuously illuminated. This sequence will be repeated every time the vehicle is started as long as the malfunction exists.

When the malfunction indicator is illuminated, the system may not be able to detect or signal low tire pressure as intended. TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning properly. Always check the TPMS malfunction telltale after replacing one or more tires or wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the TPMS to continue to function properly.

It is the driver's responsibility to set the tire pressure to that recommended for cold tires which is suitable for the operating situation  . Note that the correct tire pressure for the current operating situation must first be taught-in to the tire pressure monitor. If there is a substantial loss of pressure, the warning threshold for the warning message is aligned to the reference values taught-in. Restart the tire pressure monitor after adjusting the pressure of the cold tires  . The current pressures are saved as new reference values.

As a result, a warning message will appear if the tire pressure drops significantly.

The tire pressure monitor does not warn you of an incorrectly set tire pressure. Observe the notes on the recommended tire pressure  .

The tire pressure monitor is not able to warn you of a sudden loss of pressure, e.g. if the tire is penetrated by a foreign object. In the event of a sudden loss of pressure, bring the vehicle to a halt by braking carefully. Avoid abrupt steering maneuvers.

The tire pressure monitor has a yellow warning lamp in the instrument cluster for indicating pressure loss/malfunctions (USA) or pressure loss (Canada). Whether the warning lamp flashes or lights up indicates whether a tire pressure is too low or the tire pressure monitor is malfunctioning: • if the warning lamp is lit continuously, the tire pressure on one or more tires is significantly too low. The tire pressure monitor is not malfunctioning.

• USA only: if the warning lamp flashes for around a minute and then remains lit constantly, the tire pressure monitor is malfunctioning.

USA only: if there is a malfunction with the tire pressure monitor it can take more than ten minutes until the malfunction is shown by the tire pressure warning lamp flashing for approximately one minute and then lighting up continuously. When the malfunction has been rectified, the tire pressure warning lamp goes out after a few minutes of driving.

The tire pressure values indicated by the onboard computer may differ from those measured at a gas station with a pressure gauge. The tire pressures shown by the onboard computer refer to those measured at sea level. At high altitudes, the tire pressure values indicated by a pressure gauge are higher than those shown by the on-board computer. In this case, do not reduce the tire pressures.

The operation of the tire pressure monitor can be affected by interference from radio transmitting equipment (e.g. radio headphones, two-way radios) that may be being operated in or near the vehicle.

Checking the tire pressure electronically

■ Make sure that the SmartKey is in position 2 in the ignition lock  .

■ Press the or
button on the
steering wheel to select the Service menu.

■ Press the or
button to select
Tire Pressure.

■ Press the button.

The current tire pressure of each tire is shown in the multifunction display.

If the vehicle has been parked for longer than 20 minutes, the Tire pressure will be displayed after driving a few minutes message appears.

After a teach-in process, the tire pressure monitor automatically detects new wheels or new sensors. As long as a clear allocation of the tire pressure value to the individual wheels is not possible, the Tire Pressure Monitor Active display message is shown instead of the tire pressure display. The tire pressures are already being monitored.

If an emergency spare wheel is mounted, the system may continue to show the tire pressure of the wheel that has been removed for a few minutes. If this occurs, note that the value displayed for the position where the spare wheel is mounted is not the same as the current tire pressure of the emergency spare wheel.

Tire pressure monitor warning messages

If the tire pressure monitor detects a pressure loss in one or more tires, a warning message is shown in the multifunction display. A warning tone also sounds and the tire pressure warning lamp lights up in the instrument cluster. Each tire that is affected by a significant loss of pressure is highlighted in the pressure display.

• If the Correct Tire Pressure message appears in the multifunction display, the tire pressure in at least one tire is too low and must be corrected at the next opportunity.

• If the Check Tires message appears in the multifunction display, the tire pressure in one or more tires has dropped significantly and the tires must be checked.

• If the Warning Tire Malfunction message appears in the multifunction display, the tire pressure in one or more tires has dropped suddenly and the tires must be checked.

If the wheel positions on the vehicle are rotated, the tire pressures may be displayed for the wrong positions for a short time. This is rectified after a few minutes of driving, and the tire pressures are displayed for the correct positions.

Restarting the tire pressure monitor

When you restart the tire pressure monitor, all existing warning messages are deleted and the warning lamps go out. The monitor uses the currently set tire pressures as the reference values for monitoring. In most cases, the tire pressure monitor will automatically detect the new reference values after you have changed the tire pressure. However, you can also define reference values manually as described here.

The tire pressure monitor then monitors the new tire pressure values.

■ Set the tire pressure to the value recommended for the corresponding driving situation on the Tire and Loading Information placard on the B-pillar on the driver's side  .

Additional tire pressure values for different loads can also be found on the tire pressure table on the inside of the fuel filler flap  .

■ Make sure that the tire pressure is correct on all four wheels.

■ Make sure that the SmartKey is in position 2 in the ignition lock.

■ Press the or
button on the steering wheel to select the Serv. menu.

■ Press the or
button to select
Tire Pressure.

■ Press the button.

The multifunction display shows the current tire pressure for the individual tires or the Tire pressure will be displayed after driving a few minutes message.

■ Press the button.

The Use current pressures as new reference values message appears in the multifunction display.

If you wish to confirm the restart:

X Press the button.

The Tire Press. Monitor Restarted message appears in the multifunction display.

After driving for a few minutes, the system checks whether the current tire pressures are within the specified range. The new tire pressures are then accepted as reference values and monitored.

If you wish to cancel the restart:

X Press the button.

The tire pressure values stored at the last restart will continue to be monitored.