Tire Monitoring System: Service and Repair
Tire Pressure Monitor TPMThe Concept
TPM check the inflation pressures of the four mounted tires. The system notifies if there is a significant loss of pressure in one or more tires.
Functional Requirement
In order to assure the reliable reporting of a flat tire, the system must be reset while all tire inflation pressures are correct.
Always use wheels with TPM electronics. Otherwise the system may malfunction.
NOTE: Each time a tire inflation pressure has been corrected or a wheel or tire has been changed, reset the system.
System Limitations
Caution: TPM cannot warn you in advance of sudden severe tire damage caused by outside influences.
The system does not work correctly if it has not been reset, for example, a flat tire may be indicated even though the tire inflation pressures are correct.
The system is inactive and cannot indicate a flate tire if a wheel without TPM electronics, such as a compact spare wheel, has been mounted, or if TPM is temporarily malfunctioning due to other systems or devices using the same radio frequency.
Resetting The System
Each time a tire inflation pressure has been corrected or a wheel or tire has been changed, reset the system.
1. Start the engine, but do not start driving.
2. Press the button until the yellow warning lamp in the instrument cluster lights up for a few seconds.
3. Drive off.
After several minutes of driving, the current inflation pressures in the tires are adopted as the target values to be monitored. The resetting procedure is completed automatically without further notice during the trip, which can be interrupted at any time.
Resetting is continued automatically when you continue driving.
Warning of low tire inflation pressure
The warning lamp lights up in yellow. A signal also sounds. There is a flat tire or a significant loss of tire pressure in one or more tires.
1. Cautiously reduce speed to below 50 mph/ 80 km/h. Avoid sudden braking and steering maneuvers. Do not exceed a speed of 50 mph/80 km/h.
CAUTION! If the car is not equipped with Run-Flat Tires, do not continue driving. Otherwise a severe accident could result after a tire puncture if you continue driving.
2. In the event of complete pressure loss, 0 psi/0 kPa, you can estimate the possible distance for continued driving on the basis of the following guidelines:
- With a light load:
1 person without luggage: approx. 155 miles/250 km
- With a medium load:
1 person, cargo bay full,
or
2 persons without luggage: approx. 95 miles/150 km
- With a full load:
2 persons, cargo bay full: approx. 30 miles/50 km
CAUTION! Drive cautiously and do not exceed a speed of 50 mph/80 km/h. In the event of pressure loss, vehicle handling changes. This includes reduced tracking stability in braking, extended braking distance and altered natural steering characteristics. If unusual vibration or loud noises occur during the journey, this may be an indication that the damaged tire has finally failed. Reduce your speed and pull over as soon as possible at a suitable location. Otherwise parts of the tire could come loose, resulting in an accident. Do not continue driving.
Malfunction
The yellow warning lamp flashes and then lights up continuously; A flat tire cannot be detected
This warning is shown in the following situations:
- If there is a malfunction. Have the system checked.
- If a wheel without TPM electronics has been mounted
- If TPM is temporarily malfunctioning due to other systems or devices using the same radio frequency.
Declaration according to NHTSA/ FMVSS 138 Tire Pressure Monitoring Systems
Each tire, including the spare, 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 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.
The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash
for approximately one minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle startups as
long as the malfunction exists. When the malfunction indicator lights up, 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.