Remaining Mileage, Function
The remaining mileage displayed immediately after oil change reset is 15,000 kilometers or 10,000 miles. The remaining mileage calculated during the service interval depends highly on the initial mileage.
Initial mileage
Start distance refers to the distance in kilometers or miles which may be driven as a minimum distance until the next service. This applies only, however, if the specified quantity of the engine oil has been added during the oil change.
The initial mileage is dependent on:
- The quality factors set (the quality factors are set to basic values at the factory. They can be changed with the STAR diagnosis tool if required by the conditions of use).
The initial mileage is not dependent on the operating conditions (evaluation of distance traveled) or any oil added.
The standard value is normally 15,000 kilometers or 10,0O0 miles. However, the value may deviate depending on the quality factors.
The initial mileage is set automatically to its starting value by the oil reset operation following each oil change. The initial mileage is an internal value for computation and cannot be displayed in the instrument cluster (A1). Display of the initial mileage is only possible with the STAR diagnosis tool. Normally the remaining mileage is displayed on the multifunction display (A1p13) in the instrument cluster (A1).
Remaining mileage
The remaining mileage immediately following an oil change is the same as the initial mileage. However, this is true only when the specified quantity of engine oil was added when the oil was changed.
The remaining mileage is the number of miles from the current mileage until service is due next. The possible interval is at least as great as the remaining mileage indicated immediately after changing the oil. However, it can be up to twice the initial mileage.
The remaining mileage depends on:
- The initial mileage
- The operating conditions (the distance traveled is evaluated for this purpose)
- Any quantities of oil added
This means that the following operating conditions are also taken into consideration by ASSYST:
Under favorable conditions such as:
- Few cold starts
- No high engine speeds
- Few short trips
- Minimum or no operation with trailer
and adding oil the driver is given a bonus which increases the remaining mileage and therefore the service interval.
It is also taken into consideration whether the car is actually driven or the engine runs at idle. For this purpose the ASSYST continuously receives data on the current vehicle operating conditions.
- Under optimum conditions only 0.6 km is calculated for each kilometer driven.
Under unfavorable operating conditions (e.g. frequent short trips, many cold starts) the remaining mileage and therefore the service interval are lower than under favorable conditions (assuming the same quality factors).
- Under unfavorable conditions up to 3 km can be calculated for each kilometer driven.
The initial mileage and remaining mileage is illustrated again in the graph at the right:
Each time the oil is changed the initial mileage and remaining mileage is set back to the starting value. The standard value of 15,000 km is shown here as the initial mileage (upper beam, cross-hatched + dark section). The initial mileage can deviate from the value of 15,000 km (e.g. 14,000 km; cross-hatched section), when the quality factors do not correspond to the basic setting. The initial mileage can also be less than 15,000 km when the specified quantity of engine oil is not added when the oil is changed. The remaining mileage (lower beam) is, however, always 15,000 km or 10,000 miles immediately following the oil change. The service interval is always at least 15,000 km or 10,000 miles.
The bonus system (favorable operating conditions or adding oil) can increase the total remaining mileage and therefore the service interval to a maximum of twice the initial mileage, here 30,000 km or 20,000 miles (white section).
However, an initial mileage of less than 15,000 km or 10,000 miles reduces the maximum achievable service interval.
See also diagrams in document "Engine oil monitoring, function". Engine Oil Monitor Function
Warning threshold (mileage)
A warning threshold for the remaining mileage can be set between 250 km and 8000 km with the STAR diagnosis tool. This warning threshold can be set differently for 3 different types of operation. The system automatically switches to the correct annual mileage depending on the calculation for the daily mileage (see table):
If the remaining mileage drops below the warning threshold set, the remaining mileage is displayed automatically.
Display of remaining mileage (display is accomplished according to the setting in kilometers or miles on the multifunction display (A1p13) in the instrument cluster):
- On driver request
- Automatically after reaching the warning threshold, 5 s after turning the ignition switch to position "2" or starting the engine:
The message and service symbol appear for 30 s: "SERVICE IN xxxx KM".
- Automatically upon expiration of the remaining mileage, 5 s after turning the ignition switch to position "2" or starting the engine:
The service symbol and message appear for 30 s: "PERFORM SERVICE".
- Automatically after exceeding the remaining mileage by more than 100 kilometers, 5 s after turning the ignition switch to position "2" or starting the engine:
The service symbol and message appear for 30 s: "SERVICE EXCEEDED BY xxxx KM".
In addition a short warning tone sounds.
The remaining mileage is indicated with a resolution of 100 km or 100 miles.
NOTE: All displays are illustrated in the document "Driver information".
The remaining mileage is displayed on a standard basis. However, the time information is also processed in the background for announcing to drivers of vehicles with low annual mileage that service is due.
The remaining mileage is compared with the remaining time daily. Under the conditions specified in the document "Remaining time function" the display switches over and the remaining time is displayed.
NOTE: If readings are missing for the ASSYST, e.g. due to failure of a sensor, substitute values stored in the control modules are used.
A corresponding entry is made in the DTC memory of the corresponding control module (continuous fuel injection control module (N3), traction system control module (N47) or instrument cluster (A1)).
The data remains stored even in the event of an operating power failure.