BMW 5 Series: Wheel hub, Tire pressure control

Wheel hub

The hub and hole circle diameter on current vehicles produced by the BMW Group was modified in 03/2014. The hub diameter was reduced from 72.5 mm to 66.5 mm. The hole pattern was modified from 5 x 120 (F01/F10) to 5 x 112 (G12/G30).

Comparison of wheel hub on F10 with that on G30

1. F10 hub
2. G30 hub

Tire pressure control

The G30 is fitted with the RDCi system that has been used in other BMW vehicles with the wheel electronics sensors manufactured by Schrader. The control unit for the system is incorporated into the DSC module.

The following conditions are required to teach-in the new wheel electronics.

Warnings

The warning system for the tire pressure control has been continually developed and modified to meet customer needs during the various development stages. The warning system provides information promptly in the event of pressure deviations and thus makes an important contribution to avoiding vehicle breakdowns as a result of insufficient tire pressures.

At present it is possible to distinguish between three warning levels.

Warning level 1

Warning level 1 Check Control message in the G30

1. Tire pressure information
2. Tire pressure slightly below the setpoint value, continued driving permissible

Warning level 1 is a message to the customer that the tire pressure has dropped as a result of natural diffusion (tire pressure loss). There are no technical problems and it is possible to drive on without concern. For this reason, the KOMBI instrument cluster is showing an information symbol only.

Warning level 2

Warning level 2 Check Control message in the G30

1. Inflate tires
2. Tire pressure too low, continued driving at a maximum speed of 130 km/h (80 mph) permitted

The warning level 2 message is shown when the tire pressure has dropped below the legal threshold and the customer's comfort and safety is impaired. A Check Control message and a yellow warning light are displayed accordingly in the KOMBI instrument cluster. It is, however, possible to drive on at moderate speeds. The tire pressure should, however, be corrected as soon as possible.

Warning level 3

Warning level 3 Check Control message in the G30

1. Tire pressure loss, rear left
2. Tire pressure loss, stop with care

The yellow warning light is shown if the tire pressure drops suddenly or falls below the warning level 3 threshold. The customer should stop with care and check the tires visually. If possible, the tire pressure should be corrected.

It is possible to drive on at a maximum speed of 80 km/h (50 mph) if the vehicle has run-flat tires (RSC).

Notes for Service

All three warnings are an indication of a loss in tire pressure. The system is working correctly and faultlessly as to monitor the tire pressures. Electrical vehicle diagnosis is not necessary in this case, as no fault memory entry has been stored.

In the event of warning level 2 and warning level 3, the tire and the tire valve must also be checked for leaks or damage.

The manufacturer's information must be observed in the event of any work on the wheels and tires.

Failure to observe these requirements can lead to serious accidents.

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