Procedures
System LearningThe Tire Pressure Monitoring begins to "learn" the wheels after a wheel change, wheel transmitter replacement or update of the tire settings. During this process, the Tire Pressure Monitoring recognizes the tires and their locations. The on-board computer displays the message "TPM is learning, monitoring not act.".
The Tire Pressure Monitoring requires a certain amount of time to learn the wheels. During this time, the current tire pressures are not available on the on-board-computer:
- The tire pressure warning light remains lit until all wheels have been learned.
- The display of the tire pressure function of the on-board computer shows lines.
- The required pressures for cold tires at 68 �F (20 �C) are indicated in the Info pressure display in the tire pressure menu.
Position and pressure information is displayed as soon as the Tire Pressure Monitoring has assigned the wheels identified as belonging to the vehicle to the correct wheel positions. The wheel learning process takes place exclusively when the vehicle is being driven (vehicle speed above 25 km/h (16 mph)).
- Check the tire pressure for all wheels on the "Info pressure" display.
- Correct the tire pressure to the required pressure if necessary.
Changing a wheel and replacing tires
- New wheels must be fitted with radio transmitters for the Tire Pressure Monitoring. Before tires are changed, the battery charge state of the wheel transmitters should be checked.
- Switch the ignition off when changing a wheel. The tire settings on the on-board computer must be updated after changing a wheel. If the tire settings are not updated, the message "Wheel change? Input new TPM settings!" is displayed on the on-board computer.
- Update the on-board computer settings when the vehicle is stationary the next time.
Warning light
Warning!:
Your vehicle has also been equipped with a Tire Pressure Monitoring (TPM) malfunction indicator when the system is not operating properly.
The TPM malfunction indicator is combined with a low tire pressure telltale.
When the system detects a malfunction, the telltale will flash for approx. one 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.
TPM malfuntions may occur for a variety of reasons, including the installation of replacement or alternate tires or wheels on the vehicle that prevent the TPM from functioning properly. Always check the TPM 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 TPM to continue to function properly.
The warning light in the speedometer lights up:
- When a loss in pressure has been detected.
- When learning newly mounted wheels/wheel sensors, as long as the vehicle's own wheels have not yet been recognized.
In the event of a defect in Tire Pressure Monitoring or a temporary fault, the warning light in the speedometer flashes for approx. one minute and then remains continuously illuminated.
The tire pressure warning light in the instrument panel goes out only when the cause of the fault has been rectified.
Partial monitoring
Monitoring of the other wheels is continued if there is a fault in one or two wheel transmitters.
- The tire pressure warning light lights up.
- The message "TPM partial monitoring" is displayed on the on-board computer.
- No tire pressures are displayed on the onboard computer for wheels with faulty wheel transmitters.
No monitoring
In the event of faults the Tire Pressure Monitoring cannot monitor the tire pressure.
The warning light in the speedometer flashes for approx. one minute and then remains continuously illuminated and a corresponding message appears on the on-board computer.
Monitoring is not active when:
- The Tire Pressure Monitoring is faulty,
- wheel transmitters for the Tire Pressure Monitoring are missing,
- during the learning phase after the tire settings have been updated,
- after a wheel change without updating the tire settings,
- more than four wheel transmitters are detected,
- there is external interference by other radio sources, e.g. wireless headphones,
- tire temperatures are too high.
Pressure increase as the result of temperature increase
A Tire pressure
B Tire temperature
C Tire pressures for cold tires
D Tire pressure for hot tires
E Pressure increase as the result of temperature increase
F Pressure drop in faulty/leaking tires
1. Required-pressure line
2. Warning stage 1
(from 4 to 7 psi (0.3 bar to 0.5 bar))
3. Warning stage 2
At speeds below 100 mph (160 km/h):
(from 7 psi (0.5 bar))
At speeds above 100 mph (160 km/h):
(from 5 psi (0.4 bar))
In accordance with physical principles, the air pressure changes as the temperature changes. The tire pressure increases or decreases by around 1.5 psi (0.1 bar) for every 18 �F (10 �C) change in temperature.
The Tire Pressure Monitoring takes this relationship between tire pressure and temperature into account.
Tire pressure specifications
Information on tire pressure for public roads can be found on the tire-pressure plate in the left door aperture. These values apply to cold tires at 68 �F (20 �C) ambient temperature.