Mercedes-Benz GLC : Tire pressure / Tire pressure monitoring system

Function of the tire pressure monitoring system

DANGER Risk of accident due to incorrect tire pressure

Each tire, including the spare (if provided), should be checked monthly when cold and then inflated to the inflation pressure recommended by the vehicle manufacturer on the vehicle placard or tire inflation pressure label. (If your vehicle has tires of a different size than the size indicated on the vehicle placard or tire inflation pressure label, you should determine the proper tire inflation pressure for these 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 is significantly underinflated. Accordingly, if 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.

Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when 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 indicator lamp will flash for approximately a minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle start-ups 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.

The system checks the tire pressure and the tire temperature of the tires installed to the vehicle by means of a tire pressure sensor.

The tire pressure and the tire temperature appear in the on-board computer.

If there is a substantial pressure loss or if the tire temperature is excessive, you will be warned in the following ways:

• Via display messages.
• Via the warning lamp in the instrument cluster

The tire pressure monitoring system is only an aid. It is the driver's responsibility to set the tire pressure to the recommended cold tire pressure suitable for the operating situation.

In most cases, the tire pressure monitoring system will automatically update the new reference values after you have changed the tire pressure. You can, however, also update the reference values by restarting the tire pressure monitoring system manually.

System limits

The system may be impaired or may not function particularly in the following situations:

• The tire pressure has been set incorrectly
• Sudden pressure loss caused by a foreign object penetrating the tire, for example
• There is a malfunction caused by another radio signal source

Checking the tire pressure with the tire pressure monitoring system

Requirements:

• The ignition is switched on.

On-board computer:

Service Tires

One of the following displays appears:

• Current tire pressure and tire temperature of the individual wheels:

• Tire pressure will be displayed after driving a few minutes
• Tire Pressure Monitor Active: the teach-in process of the system is not yet complete. The tire pressures are already being monitored.

  Compare the tire pressure with the recommended tire pressure for the current operating condition. Observe the notes on tire temperature.

The values displayed in the on-board computer may deviate from those of the tire pressure gauge as they refer to sea level. At high elevations, the tire pressure value indicated by a pressure gauge are higher than those shown by the on-board computer. In this case, do not reduce the tire pressure.

Restarting the tire pressure monitoring system

Requirements:

• The recommended tire pressure is correctly set for the respective operating status on all of the wheels.

Restart the tire pressure monitoring system in the following situations:

• The tire pressure has changed.
• The wheels or tires have been changed or newly installed.

On-board computer:

Service Tires

Swipe downwards on Touch Control on the left-hand side of the steering wheel. The Use Current Pressures as New Reference Values? message is shown in the multifunction display.

To restart, press Touch Control on the lefthand side of the steering wheel.

The Tire Press. Monitor Restarted message is shown in the multifunction display.

Current warning messages are deleted and the yellow warning lamp goes out.

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

Be sure to also pay attention to the following related topic:

• Notes on tire pressure