maintenance reset VOLKSWAGEN PASSAT 2008 Owners Manual

x If there are snow chains on the tires. Using snow chains can cause the system to give false warnings because snow chains increase tire circumference.
The Tire Pressure Monitoring System Ç may not react at first or may not react at all when you are driving in a sporty manner, or on snow-covered or unpaved roads, when you are driving with snow chains, or in certain other situations. A change in the tread circumference of a tire is signaled by the Tire Pressure Monitoring System indicator in the instrument cluster (telltale).
The tire pressure recommended for the tires originally installed on the vehicle is on a sticker on the driver door jamb, Tires.
Each tire, including the spare (if provided), should be checked monthly when cold and 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 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 is 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.
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 telltale will flash for approximately 1 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 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.
Resetting and recalibrating the benchmark tire pressure
The SET button for the Tire Pressure Monitoring System is in the glove compartment ⇒ fig. 130. The SET button resets the benchmark tire pressure used by the TPMS to the current tire pressure in the tires based on the circumference of the tires. To reset the TPMS, switch on the ignition and then press and hold the SET button until you hear a confirmation chime. The chime usually sounds after a couple of seconds. The SET button must be pressed for at least 2 seconds but no more than 30 seconds each time the tire pressure in one or more tires has been adjusted or after one or more tires has been changed, exchanged, or repaired. The new tire pressures are stored in the system only after at least 20 minutes of normal driving.
If you use the SET button to reset the benchmark tire pressure when your tires do not have the correct tire pressure, this will prevent the TPMS from working properly. It may then give false warnings or may not give any warning even if the tire pressure is too low.
For this reason, it is vital to make certain that all 4 tires are inflated to the correct pressure when they are cold before pressing the SET button. Cold tire tires are tires that have not been driven more than a couple of miles (kilometers) at low speed within the last 3 hours.
Use the SET button to reset the benchmark TPMS pressure in the following situations:
x After installing tires on your vehicle that have recommended cold tire inflation pressures that are different from the tires that were taken off.