Specifications

20
Testing Testing Engine Systems
1— Green lamp—20% of total fuel calculated consumption value
2— Green lamp—40% of total fuel calculated consumption value
3— Green lamp—60% of total fuel calculated consumption value
4— Green lamp—80% of total fuel calculated consumption value
5— Green lamp—100% of total fuel calculated consumption value
6— Yellow lamp—100% of total fuel calculated consumption value—service reminder
7— Red lamp—108% of total fuel calculated consumption value—service past due
Figure 4-2 Sample SIA III lamp display
BMW recommends that most 1999 and newer vehicles use synthetic oil with oil changes
performed at 15,000-mile intervals. Depending on fuel consumption, the SIA system may turn on
the yellow LED sooner or later than actual 15,000 miles driven.
Services will always alternate between “Oil” and “Inspection.” Services can be reset early without
affecting the time to the next service (as with SIA II) because the calculation for SIA III is not
mileage based. However, note that resetting a service early means that the system will use the
reset as the new starting point for calculating fuel consumption until the next service.
NOTE:
i Note the following regarding SIA III:
• This system is designed to calculate normal driving fuel consumption with an equivalency of
approximately 15,000-mile intervals. A greater number of early resets will cause the service
lights to vary more from actual odometer mileage.
• Field reports indicate many BMW repair shops recommend changing oil more frequently than
the 15,000-mile interval. Most shops are not resetting the service lamps early when they
change the oil unless the service lamps reset is or will be due soon.
SIA IV
SIA IV is used on 1999/2000 and newer 3 Series (E46) as well as on most other 2001 and newer
models. This type instrument cluster no longer has the green, yellow and red lights, but instead
uses a digital countdown system. With every ignition cycle, the instrument cluster briefly displays
the next scheduled service and the remaining miles before the service is due. A flashing message
and a minus symbol before the mileage display indicates that a service is past due. As with SIA
III, if the vehicle is driven hard with higher than normal fuel consumption, the mileage count down
will be quicker.
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