Specifications

Testing Testing Engine Systems

• 5 green lamps—The number of illuminated lamps decreases as the time for the next

inspection approaches. Each green LED represents approximately 1500 miles.

• 1 yellow lamp—When all green lamps are off and only the yellow lamp is illuminated along

with “Oil Service” or “Inspection,” service is due.

• 1 red lamp—Maintenance is overdue when this lamp is illuminated.

1— Green lamps

2— Yellow lamp

3— Red lamp

Figure 4-1 Sample SIA lamp display

Vehicles using SIA II have oil changes due about every 7500 miles and inspections about every

15,000 miles. When service is due, all green LEDs will be out and the yellow LED will be lit and

may stay on when the engine is running. In addition, “Oil Service” or “Inspection” will be

illuminated, indicating what type of service is required. After the vehicle has been driven an

approximate additional 1,000 miles, the red LED will illuminate along with the yellow LED (usually

staying on when the engine is running).

The Oil and Inspection resets are two separate functions. Depending on driving conditions, the

time to service may be less than 7500 miles but not more. Services alternate between Oil and

Inspection. Resetting a service early or before the yellow lamp is on causes the next service to

also set earlier than the vehicle mileage will indicate.

SIA III

The SIA III is used on the E38, E39, E53 from 1996 to the present, though it was not used on the

E36 until 1999. SIA III uses the same green, yellow and red LEDs as SIA II, along with the

corresponding Inspection message. The difference is that SIA III uses only fuel consumption using

the DME ti input (injection pulse) to calculate the service interval. Each green LED represents 20%

of the total fuel calculated consumption value (variable according to engine and model) that is

stored in the SIA memory. The yellow LED represents 100% of the total fuel consumption stored

value, and the red LED represents 108%. If the vehicle is driven hard, more fuel will be consumed

and the LEDs will count down more quickly.

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