Wheels, Tires, Alignment: Overview Porsche Cayenne I

Overview of tires and wheels (standard)

1. The chart of tires and wheels for summer and winter should be taken from Technical Information (TI) Group 4.
2. When replacing summer tires, pay close attention to the tire specification number. The specification characters N1, N2, N3 and N0 distinguish the summer tires specially authorized by Porsche from other models of the same tire type and size.

Summer tires (excerpt)

Note. When mounting the wheel on the vehicle, observe the mounting specifications of the wheel bolts.

1. The chart of tires and wheels for summer and winter should be taken from Technical Information (TI) Group 4.
2. When replacing summer tires, pay close attention to the tire specification number. The specification characters N1, N2, N3 and N0 distinguish the summer tires specially authorized by Porsche from other models of the same tire type and size.

Summer tires (excerpt)

Note. When mounting the wheel on the vehicle, observe the mounting specifications of the wheel bolts.

1. The chart of tires and wheels for summer and winter should be taken from Technical Information (TI) Group 4.
2. When replacing summer tires, pay close attention to the tire specification number. The specification characters N1, N2, N3 and N0 distinguish the summer tires specially authorized by Porsche from other models of the same tire type and size.

Summer tires (excerpt)

Note. When mounting the wheel on the vehicle, observe the mounting specifications of the wheel bolts.

1. The chart of tires and wheels for summer and winter should be taken from Technical Information (TI) Group 4.
2. When replacing summer tires, pay close attention to the tire specification number. The specification characters N1, N2, N3 and N0 distinguish the summer tires specially authorized by Porsche from other models of the same tire type and size.

Summer tires (excerpt)

Note. When mounting the wheel on the vehicle, observe the mounting specifications of the wheel bolts.

General information on the tire pressure monitoring system (RDK)

The tire pressure monitoring system is designed to constantly monitor the tire pressure during driving and when standing. One set of electronics per tire is mounted in the rim well base. The wheel electronics transmits approx. once every minute its own identification number to identify wheel position, the battery service life fault status, and the actual measured tire pressure to an antenna mounted in the wheel housing. These measure tire pressure and temperature at regular intervals and transfer the values to a central control unit via a high-frequency route. The control unit evaluates the information and transfers the data to the instrument cluster if required. In this way, the driver is warned and informed if the tire pressure has to be corrected.

In the event of a loss in pressure greater than 0.2 bar per minute, the wheel electronics switches to fast transmission mode for 280 seconds and transmits the above signals every second.

The advantages of the system are

Safety

1. Early warning of gradual loss of tire pressure.
2. In the event of serious loss of pressure the driver is warned immediately, the wheel electronics switching to fast transmission mode.
3. Immediate warning of serious loss of pressure when standing (flat tire).

Comfort

1. Tire pressure checking only necessary when warning appears in the instrument cluster display.

Service life of tires

1. Tire wear is minimized by inflation at the correct air pressure at all times.
2. Fuel consumption is reduced.

Service life of wheel electronics during storage

1. During storage the wheel electronics is in the idle state. This means it transmits no signals.
2. The wheel electronics is only activated (transmits for the first time) after being subjected to an air pressure of at least 2 bar for a period of 2 minutes. Until this time the service life is higher than in the activated operating state (approx. 4-7 years).

General information on wheel electronics

The tire pressure monitoring system is designed to constantly monitor the tire pressure during driving and when standing. One set of electronics -A- per tire is mounted in the rim well base. These measure tire pressure and temperature at regular intervals and transfer the values to a central control unit via a high-frequency route. The control unit evaluates the information and transfers the data to the instrument cluster if required. In this way, the driver is warned and informed if the tire pressure has to be corrected. see scheme 43

There are two versions of the wheel electronics -A-. In the case of the Cayenne, versions with amplified transmitting power are used. These transmit in the high frequency range: see scheme 43

1. 433 MHz or 315 MHz.

The following points can be used as distinguishing characteristics

1. The labelling, 433 MHz or 315 MHz
2. The part number
3. 4 stars on left and right of the slot (wheel electronics with amplified transmitting power only)
4. And/or the color (dark grey 433 MHz; light grey 315 MHz).

Scheme 1

A - Wheel electronics

B - Valve complete (No. 2 to No. 7)

1 - Self-locking (Torx) fastening screw

2 - Valve cap (plastic)

3 - Valve insert

4 - Union nut

5 - Washer chamfered on both sides

6 - Bead seat sealing ring

7 - Valve

Scheme 2

Note. For vehicles with a tire pressure monitoring system, the valve and wheel electronics are only replaced in exceptional cases! The following points can make replacement necessary!

Valve complete with screw -1 to 7- has to be replaced if: (Scheme 1)

1. The wheel electronics are removed
2. The self-locking -1- fastening screw is loose (Scheme 1)
3. The bead seat sealing ring -6- is porous or damaged (Scheme 1)
4. The valve body -7- is bent. (Scheme 1)
5. The union nut -4- is loose. (Scheme 1)

Scheme 3

The wheel electronics -A- must be replaced if: (Scheme 2)

1. The housing is visibly deformed
2. The filter surface (square, porous section on back of wheel electronics) is so badly soiled that it can no longer be cleaned by wiping
3. Tire sealant (tire sealing liquid) has been used
4. The service life of the battery has expired
5. There is a fault within the wheel electronics.

After removal of the tire, the wheel electronics -A- can be seen at the valve in the outer rim well base. (Scheme 3)

1. Release wheel electronics from valve using a Torx socket screwdriver T 20 (if necessary, counter with a suitable assembly pin, e. g. steel pin Ø approx. 1.8 mm in bore at valve foot) and remove.

2. Then unscrew union nut and remove valve.