Sprinter 3500 L5-2.7L DSL Turbo (2004)
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Road Conditions.
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Incline, Decline and Altitude.
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Trailer Operation, Loading.
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Engine Coolant Temperature.
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Cruise Control Operation.
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Sporty Driving Style.
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Low and High ATF Temperature.
DOWNSHIFT SAFETY
Selector lever downshifts are not performed if inadmissible high engine rpm is sensed.
ADAPTATION
To equalize tolerances and wear, an automatic adaptation takes place for:
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Shift Time.
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Clutch Filling Time.
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Clutch Filling Pressure.
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Torque Converter Lock-Up Control. Adaptation data may be stored permanently and to some extent, can be diagnosed.
Driving Style Adaptation
The shift point is modified in steps based on the information from the inputs. The control module looks at inputs such as:
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vehicle acceleration and deceleration (calculated by the TCM).
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rate of change as well as the position of the throttle pedal (fuel injection information from the ECM).
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lateral acceleration (calculated by the TCM).
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gear change frequency (how often the shift occurs).
Based on how aggressive the driver is, the TCM moves up the shift so that the present gear is held a little longer before the next upshift. If the driving
style is still aggressive, the shift point is modified up to ten steps. If the driving returns to normal, then the shift point modification also returns to the
base position.
This adaptation has no memory. The adaptation to driving style is nothing more than a shift point modification meant to assist an aggressive driver. The
shift points are adjusted for the moment and return to base position as soon as the inputs are controlled in a more rational manner.
Shift "Time Adaptation (Shift Overlap Adaptation, Working Pressure)
Shift time adaptation is the ability of the TCM to electronically alter the time it takes to go from one gear to another. Shift time is defined as the time it
takes to disengage one shift member while another is being applied. Shift time adaptation is divided into four categories:
1. Accelerating upshift, which is an upshift under a load. For shift time adaptation for the 1-2 upshift to take place, the transmission must shift from
1st to 2nd in six different engine load ranges vs. transmission output speed ranges.
2. Decelerating upshift, which is an upshift under no load. This shift is a rolling upshift and is accomplished by letting the vehicle roll into the next
gear.
3. Accelerating downshift, which is a downshift under load. This shift can be initiated by the throttle, with or without kickdown. The shift selector
can also be used.
4. Decelerating downshift, which is accomplished by coasting down. As the speed of the vehicle decreases, the transmission downshifts.
Fill Pressure Adaptation (Apply Pressure Adaptation, Modulating Pressure)
Fill pressure adaptation is the ability of the TCM to modify the pressure used to engage a shift member. The value of this pressure determines how firm
the shift will be.
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If too much pressure is used, the shift will be hard.
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If too little pressure is used, the transmission may slip.
The pressure adjustment is needed to compensate for the tolerances of the shift pressure solenoid valve. The amount the solenoid valve opens as well as
how quickly the valve can move, has an effect on the pressure. The return spring for the shift member provides a resistance that must be overcome by the
pressure in order for shift member to apply. These return springs have slightly different values. This also affects the application pressure and is
compensated for by fill pressure adaptation.
Fill "Time Adaptation (Engagement "Time Adaptation)
Fill time is the time it takes to fill the piston cavity and take up any clearances for a friction element (clutch or brake). Fill time adaptation is the ability of
the TCM to modify the time it takes to fill the shift member by applying a preload pressure.
CONTROLLER MODES OF OPERATION
Permanent Limp-In Mode
