Take-up table is the one that defines pressure during start of movement. It is a bit different in various transmissions but in general rule it’s always RPM dependent.
OL Dual Clutch take-up #
Dual Clutch transmissions use Take-up table RPM x PPS (throttle pedal position sensor). After selecting DRIVE mode (1st or reverse gear) GCU will be in IDLE take-up mode (1) take-up pressure will be built once PPS gets pressed (HTG hint: it’s good to configure PPS and TPS in IO assignments tab in case of DBW application so it’s the pedal defining take-up wish instead of constantly floating to control idle speed throttle). Higher temperature requires slightly higher pressures, also this can be used as protection from overheating clutches during excessive take-ups.Once clutch slip is at desired level transmission will exit take-up mode and GCU will apply pressure from Clutch Pressure tables.
Closed Loop dual clutch takeup #
CL DC takeup learns automatically during FIRST takeup on each of the clutches. In order to complete TU learning process has to be done fully and as follows:
- Place vehicle on FLAT surface without obstacles – adaptation requires to roll car some distance in each direction.
- Hold brake pedal (has to be configured)
- Engage D or M or R mode.
- Release brake pedal
- Takeup learning is performed – You can notice clutch pressure gradually building and dropping until GCU finds pressure level causing smooth and continuous creep.
- Once learning is done GCU won’t drop pressure anymore and car will keep on creeping forward.
- Push the brake and come to complete stop. Engage next gear and repeat the process.
Takeup relation to PPS position and CREEP strength are defined in Takeup Strength table. Start with low values and increase gradually to Your preference.
Example: CL DCT TU
Take-up mode statuses: #
- Idle: GCU is in R or D/M mode ready to take-up but it’s not active. Stays idle until requirements to activate take-up are valid.
- Take-up ramp down: pressure is being decreased (ramped down) to idle.
- Take-up: take-up is active and ongoing.
- Take-up drive: pressure is being switched from take-up pressure to clutch pressure value.
- Drive: take-up has finished and GCU is in clutch pressure (normal run) state.
- Disabled: Neutral or Parking mode.
- CbW: CbW is greater than 0% during normal run mode.
- CbW Take-up: is greater than 0% during take-up mode. If CbW at this state exceeds 50% mode is changed to 11 – switched to normal run + CbW
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