Tire Pressure Monitor Systems Audi S4 B8

DESCRIPTION & OPERATION

Note. Whenever tire pressure is adjusted, the adjusted pressure has to be stored again. If a tire or tire pressure sensor was changed or relocated, the TPMS must be initialized. See RESET PROCEDURES .

TIRE PRESSURE MONITOR (TPM) SYSTEM

The Tire Pressure Monitor (TPM) system is used for continuous monitoring of tire pressure in all 4 road wheels while the vehicle is moving. It assists the driver in checking tire pressures, and provides warning messages on the instrument cluster display in case of loss of tire pressure.

The TPMS may fail to operate correctly due to the following conditions

1. If warning indicators are displayed at the end of a learning phase, it means that the system cannot recognize which wheels are mounted on the vehicle. This may be because one or more wheels were mounted lacking a wheel sensor.
2. A wheel sensor or other component may have failed.
3. The system recognizes more than 4 wheels are present on the vehicle (i.e., when additional winter tires are being transported on the vehicle and are transmitting data).
4. A wheel was changed, and the new tire was not initialized.
5. If vehicle is being operated with snow chains, system function can be affected by the shielding effect of the chains.
6. System is not available due to a malfunction.
7. Other transmitting devices with the same frequency (i.e., headphones with integrated radio) are emitting an electromagnetic field which can cause temporary interference in the system.

Note. If system is malfunctioning due to interference, eliminate cause of interference and re-initialize system.

TIRE PRESSURE MONITOR WARNING DISPLAY

As soon as a wheel sensor senses a significant loss of air pressure in one or more tires, the sensor(s) sends signals (values) to the tire pressure monitoring antenna which then transfers the values to the tire pressure control module. The control module transfers the values to the driver information system in the instrument cluster which displays a flat tire symbol and text message which reads "CHECK TIRE PRESSURE". After a few seconds, the message is replaced by the regular display (press CHECK button to show message again).

The low pressure warning light in the instrument cluster illuminates when

1. Tire pressure is 7 psi (48 kPa) lower than it should be.
2. One or more wheels are installed without a tire pressure sensor.
3. Winter tires are installed.
4. Incorrect pressure sensors are installed.

When a tire pressure monitoring system malfunction occurs, it will be indicated when the ignition is turned ON and the yellow malfunction lamp in the instrument cluster will flash for one minute and then stay ON, and a yellow TPMS is shown in the display (on newer models, more explicit messages may be displayed).

RESET PROCEDURES

Note. Whenever tire pressure is adjusted, the adjusted pressure has to be stored again. See STORING TIRE INFLATION PRESSURES . If a tire or tire pressure sensor was changed or relocated, the TPMS must be initialized. See WHEEL CHANGE INITIALIZATION .

When the tire pressure warning light illuminates and warning message appears, immediately check air pressure of all tires and adjust to the specified pressure. Store new pressures. Ensure warning indicators go out.

STORING TIRE INFLATION PRESSURES

Note. Whenever tire pressure is adjusted, the specified pressures must be reprogrammed.

1. Adjust air pressure in all tires to specifications (as provided on vehicle's tire pressure label).
2. Turn ignition ON.
3. On the center instrument cluster display (MMI), press the CAR function button. (Scheme 14)
4. Select "TIRE PRESSURES MONITORING". Then "STORE CURR. TIRE PRESSURES" or STORE NOW".

Scheme 14

WHEEL CHANGE INITIALIZATION

Note. Each time a tire and/or tire pressure sensor/valve is changed, the new tire sensor/valve must be initialized. The tire and/or sensor change is incomplete if initialization process is not performed.

Note. Initializing the tire pressure sensor is a basic requirement for the tire pressure monitoring system to function properly.

Note. The vehicle must stand for 20 minutes and then be driven on a 10 minute initialization drive at speeds greater than 16 mph (25 K/ph)

1. Adjust air pressure in all tires to specifications (provided on vehicle's tire pressure label).
2. Turn ignition ON.
3. On the center instrument cluster display (MMI), press the CAR function button. (Scheme 14)
4. Select "TIRE PRESSURES MONITORING". Then "STORE CURR. TIRE PRESSURES" or STORE NOW".

Note. The system will detect a malfunction if the control module is not ready for initialization because the 20 minute waiting period was not completed. The system will only initialize the tire pressure sensors automatically after a 20 minute waiting period.

DISMOUNTING/MOUNTING PROCEDURES

Note. When reusing tire pressure sensors, inspect the connection between sensor and metal valve for damage.

Note. Tire pressure is also dependent on temperature of the tire. For every 18°F (10°C) increase in tire temperature, tire pressure increases about 1.5 psi (10 kPa). Tire pressure should only be adjusted when tires are cold (about the same as ambient air temperature).

Note. Whenever tire pressure is adjusted, the adjusted pressure has to be stored again. If a tire or tire pressure sensor was changed or relocated, the TPMS must be initialized. See RESET PROCEDURES .

Removal

Note. Currently 2 types of tire pressure sensors are used; (Scheme 15)and (Scheme 18).

Note. The nickel plated valve insert must be replaced each time the tire is changed.

1. Remove tire and wheel assembly from vehicle.
2. Dismount tire from wheel following tire changer manufacturer's instructions while paying special attention to the following to avoid damaging the pressure sensor: Press tire off both rim edges on opposite side to metal valve. Turn wheel on tire mounting equipment so that the valve/tire pressure sensor is opposite the mounting head.
3. To remove Beru System tire pressure sensors; NOTE: To perform this procedure, Torque Wrench (V.A.G. 1410) and Socket (V.A.G. 1410/1) is required. While holding tire pressure sensor against wheel rim, remove Torx fastener. (Scheme 16) While counter-holding metal valve body (for example, 2-mm twist drill or counter holding tool), remove union nut and metal valve. (Scheme 17) Remove and discard valve insert from the valve stem.
4. To remove Siemens System tire pressure sensors; NOTE: To perform this procedure, Torque Wrench (V.A.G. 1331) is required. While holding sensor valve body, remove union nut and dismount valve. (Scheme 19) Remove and discard the valve insert from the valve stem. Remove and discard the sealing washer and seal. (Scheme 18)

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Installation

Note. When reusing tire pressure sensors, inspect the connection between sensor and metal valve for damage. It is also necessary to replace the valve nut, nickel plated valve insert, sealing ring, sealing washer and valve cap when reusing tire pressure sensors.

1. To install Beru System tire pressure sensors; NOTE: To perform this procedure, Torque Wrench (V.A.G. 1410) and Socket (V.A.G. 1410/1) is required. Install metal valve body, and while counter-holding valve (for example, 2-mm twist drill or counter holding tool (Scheme 17)), tighten union nut to specification. See «TORQUE SPECIFICATIONS»(/audi/s4/b8-2008-2011/remont/reset-procedures/#tire-pressure-monitor-systems) Press and hold tire pressure sensor against wheel rim and tighten Torx fastener. (Scheme 16) Tighten Torx fastener to specification. See «TORQUE SPECIFICATIONS»(/audi/s4/b8-2008-2011/remont/reset-procedures/#tire-pressure-monitor-systems) NOTE: The micro-encapsulated Torx fastener must be replaced after removal.
2. To install Siemens System tire pressure sensors; NOTE: To perform this procedure, Torque Wrench (V.A.G. 1331) is required. Install the seal and sealing washer onto the sensor valve stem and install the sensor into the wheel. While holding sensor valve body securely against the wheel rim, install the union nut and tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/s4/b8-2008-2011/remont/reset-procedures/#tire-pressure-monitor-systems).
3. Mount tire on wheel following tire changer manufacturer's instructions, paying special attention to the following to avoid damaging tire pressure sensor: Make sure that tire does not contact tire pressure sensor while mounting tire. Turn the wheel on the tire mounting equipment so that valve/tire pressure sensor is opposite the mounting head.
4. Install tire and wheel assembly to vehicle.
5. Adjust inflation pressures of all tires (including spare tire), and balance tires. Store new tire pressures in system. See «RESET PROCEDURES»(/audi/s4/b8-2008-2011/remont/reset-procedures/#tire-pressure-monitor-systems__reset-procedures).

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• RESET PROCEDURES
• STORING TIRE INFLATION PRESSURES
• WHEEL CHANGE INITIALIZATION
• TORQUE SPECIFICATIONS