Automatic Transmission (MINI COOPER Only)
The Electronic Constantly Variable Transmission (ECVT) is available on the MINI COOPER. The origins of the Continuously Variable Transmission (CVT) manufactured by ZF dates back to 1974 with a revolutionary rubber drive belt. After several years of development, a new generation of ECVT has evolved, incorporating the use of a steel drive belt.
Purpose of the System
The stepless shifting pattern of the transmission provides a very comfortable drive, as well as having full vehicle performance, available at any time. The advantages of using an automatic transmission of this type are
- Low engine revolutions at constant speeds.
- Improved emission control/fuel consumption.
- Low noise, vibration and harshness levels.
- Smooth acceleration.
- Flexible driving on mountain roads.
The ECVT consists of a number of elements that are divided into three groups, depending upon their function.
Group One
Elements providing the mechanical torque flow through the transmission.
These elements are
- Planetary gear set
- Multiplate clutches
- Primary pulley
- Steel drive belt
- Secondary pulley
- Pinion shaft
- Differential unit
Group Two
These elements relate to the hydraulic system. This system enables the transmission to transmit power and to vary the ratio in a proper way, according to load conditions and driver demand.
- Hydraulic pump
- Hydraulic control unit
Group Three
These elements are externally connected to other systems.
- Ratio Control Motor
- Park/Neutral Switch
- Output Shaft Speed Sensor
- Instrument Cluster Display
- Selector Shift Mechanism
- Steering Wheel Remote Buttons (Optional)
- GIU (gearbox interface unit)
The Ratio Control Motor, Park/Neutral Switch and Output Shaft Speed Sensor are inside the transmission.
Notes
Planetary Gear Set
The planetary gear set enables the transmission to provide a drive torque in two directions, forward and reverse, to the drive shafts. Engine torque always enters the transmission through the planet carrier via the input shaft. This carrier can be directly connected to the sun-wheel by the forward multi-plate clutches. When it does, the epicyclic gear set rotates as one unit, and engine torque is transmitted directly to the primary pulley. The planet gears do not transmit any torque, therefore no mechanical loss will occur in the planetary gear set and the primary pulley will rotate in the same direction as the engine. This is the forward drive mode.
In reverse mode, the annulus of the planetary gear set is held stationary by the reverse multi-plate clutches. Three pairs of planet gears are driven by the planet carrier, forcing the sun-wheel to rotate in the opposite direction.
Scheme 237
Multiplate Clutches
There are two Multiplate wet clutch packs; one forward and one reverse. Each pack has three friction plates providing six friction surfaces. Hydraulic pressure controls the clutches to allow the vehicle to move away smoothly regardless of the degree of throttle opening and by controlling the slip, allow the vehicle to be held stationary after a drive gear is engaged. Oil from the oil cooler is directed to the clutch plates to prevent overheating of the friction surfaces.
Scheme 238
Primary Pulley, Secondary Pulley, Steel Belt
The main design feature of the ECVT is a pair of steel "V" shaped pulleys connected by a steel drive belt. The distance between centers of the primary and secondary pulley is 155 mm. Each pulley consists of one fixed half and one movable half, both having 11 degree sloping sides. A 24 mm wide "Van Doorne" push type drive belt is used to transfer torque between the pulleys. The belt is lubricated and cooled by an oil jet from a nozzle.
It is non-serviceable. Both moving halves are situated diagonally opposite to each other in order to reduce misalignment of the drive belt during shifting.
Scheme 239
Scheme 240
The steel drive belt has approximately 450 segments and is held together by 24 steel bands, 12 on each side. All the segments are of the same thickness.
Pinion Shaft
The pinion shaft creates a two-set helical gear reduction between the secondary pulley and the crown wheel. In this way, the rotational direction of the drive shafts will be correct. The reduction between the secondary pulley and the drive shafts can be made large enough to give good vehicle performance. The pinion shaft is supported by two conical bearings, one in the clutch housing and one in a separate bearing support.
Scheme 241
Differential
Drive torque on the crown wheel is transmitted to the vehicle wheels via a bevel gear differential, just as in a manual transmission. The crown wheel is bolted to the differential case with 8 bolts. The drive shafts are fitted to the differential with conventional CV joints and seals. Conical bearings are used to support the differential.
Scheme 242
Oil Pump
The pump within the transmission is an externally toothed gear pump. The engine drives it via a shaft through the hollow primary pulley shaft. The pump shaft is splined to the planet carrier, which always runs at engine speed . System pressure reaches 40 bar. The oil pressure is used both for controlling the transmission hydraulically, and for lubrication purposes.
Scheme 243
Hydraulic Control
The ECVT is controlled by a number of valves that respond to mechanical, electrical and hydraulic inputs. The control system is designed to control the pulleys and the clutches in the following three ways
- Flow to and from the primary pulley is controlled to command the correct transmission ratio for all driving conditions.
- Secondary pressure is supplied to the secondary pulley to ensure that there is always adequate clamping force onto the belt for all load conditions. A solenoid valve influences the secondary pressure control valve, optimizing the pressure and hence the belt tension between the primary and secondary pulleys. This pressure optimization improves fuel consumption.
- The clutch control consists of
- Selection of the correct clutch (forward or reverse). Engagement of forward or reverse gear via the selector mechanism operates the manual valve directing oil to the appropriate clutch.
- A solenoid valve acting on the clutch valve controls the clutch application pressure to ensure smooth clutch engagement and drive away at all throttle openings. This is needed for take off.
Pitot Pressure
Engine speed and hydraulic pressure monitoring is accomplished through two Pitot Pressure Systems. Each system consists of a pitot chamber and a pitot pipe. The pipe is stationary while the chamber, which is filled with oil and rotating at the speed to be measured.
Hydraulic Control Valves
The Hydraulic Control System consists of the following valves
- Primary Valve
- Exhaust Secondary Valve
- Cooler Flow Valve
- Constant Pressure Valve
- PWM Solenoid Clutch Valve
- Manual Valve
- Secondary Valve
- PWM Solenoid Secondary Valve
- Exhaust Valve Clutch Pressure
- Supply Valve
- Reverse Inhibitor Valve
Primary Valve
The function of the primary valve is to regulate primary pressure, controlling the primary pulley, and changing the transmission ratio. The pressure in the primary cylinder defines the position of the primary pulley mobile half. The greater the distance between the pulley halves the smaller the primary radius of the belt and the higher the transmission ratio.
Secondary Valve
The secondary valve determines the clamping force on the secondary pulley by regulating the pump pressure. The higher the clamping force, the higher the torque that can be transmitted.
Exhaust Secondary Valve
The exhaust secondary valve regulates overall maximum pressure and controls the secondary pressure in 'Low' for engine speeds up to 1600 - 2000 rpm. This valve improves creep quality that is better at lower secondary pressures. It also creates a smooth transition from the level in creep to the level in low at higher engine speeds. The valve is closed if not in low ratio.
PWM Solenoid Secondary Valve
The PWM solenoid secondary valve influences secondary valve movement, hence belt tension via secondary pulley chamber pressure. The secondary pressure solenoid further modulates the pressure acting on the secondary pressure valve. This optimizes the secondary pressure and hence minimizes losses and improves fuel consumption.
Cooler Flow Valve
The cooler flow valve controls the oil flow through the cooler when D position is engaged. The valve ensures enough oil flow during stall conditions or driving in high ratio for cooling, while ensuring sufficient system pressure is maintained at low engine speeds even under extreme temperatures.
Clutch Pressure Valve
This valve regulates the clutch pressure and allows for the adjustment of stall speed. The clutch pressure is derived from the secondary pressure and is controlled by the engine speed pitot, the primary pressure pitot and the clutch PWM solenoid pressure. The clutch valve consists of 1 valve, 2 springs and a plunger.
Exhaust Valve Clutch Pressure
The Exhaust Valve Clutch pressure has two main functions
- Limit the maximum clutch pressure.
- Protection of the gearbox from abuse.
The clutch pressure is bled into the exhaust valve, otherwise, with increasing engine speed; the pressure would limit the minimum secondary pressure too much, which would adversely affect fuel economy and could lead to damage within the gearbox.
Constant Pressure Valve
The Constant Pressure Valve establishes a base pressure that is used to supply the supply valve. The constant pressure valve acts as a filter for the supply valve and reduces disturbances in the secondary pressure. The constant pressure is also used for the ratio control depending on locking of the clutches. As the ratio approaches overdrive the constant pressure will be supplied to the clutch valve instead of the clutch PWM solenoid pressure.
Supply Valve
The Supply Valve controls the pressure function of the two pitot pressures. A higher engine pitot pressure will cause a higher supply valve pressure and a lower primary pitot pressure will cause a lower supply valve pressure. If both pitot pressures rise by the same amount the supply pressure will also increase. The supply pressure forms an input to the clutch PWM solenoid and is also used for belt lubrication and oil supply to the pitot systems.
PWM Solenoid Clutch Valve
Influences clutch application pressure by biasing the clutch valve. Permits a variety of strategies to be applied to the engagement process.
Reverse Inhibitor Valve
The Reverse Inhibitor Valve prevents the reverse clutch from being energized above a specified forward speed.
Manual Valve
The manual valve has four positions, each corresponding to a position of the selector lever inside the vehicle. Choosing reverse or drive activates one of the two clutches whereas in the neutral and park position both clutches are released. The engine can only be started with the selector lever in the neutral or park position, in all the other positions the starter circuit is inhibited.
Ratio Control Motor
The Ratio Control Motor is housed inside the transmission, adjacent to the oil cooler pipe connections. The motor and solenoids are connected to the main harness via a circular connector. The motor is operational in all transmission modes and controls the hydraulic control unit to adjust the primary pulley to the appropriate position.
Scheme 244
The motor which controls the transmission ratio is a linear actuator and a bi-polar stepper motor.
Park/Neutral Switch
The selector cam activates the park/neutral switch, which prevents the car from starting in reverse or drive and switches on the reverse lights when in reverse. The switch status is also used by the EMS 2000 in conjunction with the gear selector switch to establish the correct driving mode.
The switch is operated by a cam, which also operates the hydraulic control unit within the transmission. The selector lever via a cable to the transmission operates the cam. The switch has two positions and performs several functions, one of which is to inform the EWS immobilization unit that the transmission is in the park or neutral positions. The EWS unit will then enable the starter relay coil to be energized, thus allowing the engine to be started.
When the selector lever is in the park or neutral position and the ignition is switched on, the EMS 2000 will energize a shift lock solenoid on the selector lever. This locks the lever in the park or neutral position. The selector lever cannot be moved from the park or neutral position until the foot brake is applied.
Scheme 245
Output Shaft Speed Sensor
The ECVT transmission has a dedicated secondary speed sensor located in the differential housing. This sensor is a Hall effect sensor and produces a pulse train of approximately 73000 pulses per mile. The sensor allows for more precise calculation of transmission output speed that is used in the control strategy systems.
The secondary speed sensor is located so that the sensor tip is close to the crown wheel of the differential. By sensing the crown wheel, the signal is not affected by the different wheel speed signals when the vehicle is cornering.
Scheme 246
Scheme 247
Instrument Cluster Display
A Liquid Crystal Display in the instrument cluster shows the current drive mode and selected gear. The display includes the following characters, 'P', 'R', 'N', 'D', 'SD', '1', '2', '3', '4', '5', '6' and 'EP'. During Adaptations "X" will be displayed in front of the normal character (e.g XP).
Selector Mechanism
Selection of the required driving mode, through the selector lever inside the vehicle, activates a selector shaft within the transmission. A push/pull type cable connects the lever in the car and the shaft on the gearbox. A cam fitted to the selector shaft is also connected to the manual valve of the control system, and selects one of its five desired positions (PRNDS/M). Moving the selector lever across the gate trips a proximity sensor.
A spring and cone operated pawl mechanically locks the secondary pulley when the selector lever is moved to the Park position. If selection of park is made at speed the pawl will rattle without engaging Park. It will not engage until the vehicle speed drops below approximately 3 mph.
Scheme 248
Movement of the selector lever (or steering wheel buttons) in a forward direction, plus (+), changes the transmission up the gear ratios and movement in a rearward direction, minus (-), changes the transmission down the gear ratios.
Scheme 249
Scheme 250
GIU (GearBox Interface Unit)
The main function of the GIU is to allow communication between the ECVT and the EMS 2000. The GIU has the following functions
- Conversion of inputs from the selector lever switches (and steering wheel switches if fitted) into a CAN instruction that is read by the EMS 2000.
- Drive the LED's to display transmission mode.
- Conversion of the CAN instruction for the EMS 2000 into electrical signals to drive the ratio control motor, clutch and secondary pressure solenoids.
Gearbox Interface Unit Inputs
There are many inputs the GIU requires for correct functionality
- Selector lever switches.
- Steering wheel switches (if fitted).
- Park/Neutral switch.
- CAN messages from the EMS 2000.
Selector Lever Switches
The park, reverse, neutral and drive switch is located on the left-hand side of the selector lever, secured to the base plate with two screws. The switch is connected to the main harness by a ten-pin connector. The park, reverse, neutral, drive and manual switch has four proximity sensors that correspond to the four selector lever positions. Two further proximity sensors correspond to the manual +/- positions. The selector lever has two targets, upper and lower. The upper target is aligned with the park, reverse, neutral, drive and manual sensors and the lower target aligns with the +/- sensors.
When the selector lever is moved to the manual/sport position, the upper target moves away from the drive proximity sensor. The GIU senses this and puts the transmission into manual/sport mode. The transmission will operate in sport mode until the GIU senses that either the + or the - proximity sensor is operated, the GIU will then operate the transmission in manual mode.
Scheme 251
CAN Communication
The communication between EMS 2000 and GIU is by CAN. The EMS 2000 talks directly to the ECVT interface GIU via the CAN link. The GIU sends the EMS 2000 information on the following
- The current status of the park, reverse, neutral and drive switches.
- The current status of the sport/manual switches.
- The current status of the +/- switches (steering wheel buttons if fitted).
- The current status of the +/- switches (selector lever).
- Fault status of all active components.
- The current status of the Park/neutral switch.
The EMS 2000 provides information for the transmission GIU via a CAN-bus. The EMS 2000 controls the position of the ratio control motor indirectly (by means of instructing the GIU to control the motor to a given position).
The EMS 2000 can interrogate the GIU for fault diagnostics and to request real time data and system performance checks when the vehicle is connected to DISplus.
Notes
ECVT Gear Ratios
The ECVT transmission includes a final drive and a secondary reduction drive arrangement.
The ratios are as follow
- Final drive ratio is 4.050:1 and the secondary reduction ratio is 1.423:1.
- Low ratio of the belt and pulleys is 2.416:1, allowing a overall low ratio of 13.924:1.
- Highest ratio of the belt and pulleys is 0.443:1, which provides an overall ratio of 2.553:1.
- Reverse has on overall ratio of 15.472:1.
Scheme 252
ECVT Principles
Unlike conventional planetary automatic transmissions that provide a limited number of gear ratios, usually three, four or five, the ECVT, as its name suggests, continuously varies the gear ratio.
A low gear (low ratio) makes it easier to pull away from a rest position, the drive pulley being relatively small, while the driven pulley is large by comparison. The drive belt is used to transmit power and torque.
The ECVT uses a primary pulley and a secondary pulley. Both pulleys have one fixed half and one mobile half, controlled by hydraulic pressure. The position of the drive belt on the pulleys will determine the ratio. If the mobile half of the pulley is close to its opposite half then the drive belt is forced to travel around the outer circumference. When the pulley is open wide then this circumference is reduced. The primary and secondary pulley mobile halves are diagonally opposed so when the drive belt diameter is reduced on the primary pulley, it increases on the secondary pulley.
To pull away, a low ratio is required. To provide this, the primary pulley is open, allowing the drive belt to sit down into the pulley and forcing it to run around the outer part of the closed secondary pulley.
Scheme 253
Scheme 254
As vehicle speed increases, a higher gear ratio is required. To do this, the primary pulley gradually moves towards its fixed partner, increasing the pulley circumference. At the same time the secondary pulley is forced apart reducing pulley diameter, therefore creating a higher gear ratio.
If acceleration continues to take place, further up-shifts may be made until the drive pulley diameter is as large as possible and the driven pulley diameter is as small as possible. Therefore, for every revolution of the drive pulley the driven pulley revolves several times.
This degree of change can be controlled to ensure that the most suitable ratio is provided.
An overdrive ratio is obtained when the primary pulley is fully closed and the secondary pulley is fully open. The secondary pulley is now forced to rotate approximately two and a half times for every turn of the primary pulley.
Scheme 255
Scheme 256
Drive Plate
The engine is connected to the input shaft in the transmission, via a torsional damper, instead of the torque converter used by more conventional automatic transmissions.
Scheme 257
Selector Lever in Park or Neutral
In this condition motion is not transferred to the wheels as both clutches for reverse (2) and forward gears (4) are disengaged.
- The transmission input shaft (1) turns at the same speed as the engine.
- The reverse gear clutch (2) is disengaged.
- The forward gear clutch (4) is disengaged.
- The planetary gears (3) idle around the sun gear.
- As the sun gear does not move, neither does the primary pulley (5), the secondary pulley (7) and, subsequently, the vehicle.
Scheme 258
Selector Lever in Drive Position
Under these conditions, the epicyclic set of gears, the planetary gears (3), the sun gear and the outer ring gear are held by the forward clutch (4) that is engaged.
- The transmission input shaft (1) turns at the same speed as the engine.
- The reverse clutch (2) is disengaged.
- The forward clutch (4) is engaged.
- The planetary gears (3) the sun gear and the annular ring gear of the epicyclic train will rotate together.
- The primary pulley (5) turns at the same speed as the engine in the forward gear direction.
- The secondary pulley (7) turns in the forward gear direction at a speed that depends upon the belt ratio for that operating condition.
Scheme 259
Selector Lever in Reverse Position
Under this condition, the reverse clutch (2) is engaged and makes the annular ring gear (9) lock to the transmission case. The planetary gears (3) force the sun gear (10), the primary pulley (5) and the secondary pulley (7) to turn in the opposite direction to the transmission input shaft (1). Therefore reverse gear is now selected.
- The transmission input shaft (1) turns at the same speed as the engine.
- The reverse clutch (2) is engaged.
- The forward clutch (4) is disengaged.
- The annular gear (9) is held stationary with the transmission case by means of the reverse clutch (2).
- The planetary gears (3), which are driven directly by the transmission input shaft (1), turn around the annular gear (9). Therefore they force the sun gear (10), the pulley (5) and the secondary pulley (7) to turn in the reverse gear direction.
Scheme 260
Electronic Controls
The ECVT is based on a standard ECVT unit with electronic components fitted to control the gear ratios, the secondary pressure and the clutch pressure. The location of the components that form the steptronic transmission vary depending upon vehicle installation.
All of the control methods associated with the transmission are run as part of the EMS 2000 software. The EMS 2000 receives inputs from the main sensors of this system, communicates with the gearbox interface unit (GIU) to control the transmission, accepts driver inputs and provides information to the driver via the instrument cluster.
The control of the transmission is integrated with the EMS 2000 and a GIU enables this integration, acting as a slave/interpreter for the EMS.
EMS 2000 can control the transmission so that the input shaft speed, relative to the output shaft speed, is fixed in one of six ratios. This gives the effect that the vehicle has a six speed manual transmission with a sequential gear change.
The system protects the transmission, while in manual mode, against shifts that could be potentially dangerous or could damage the engine, for example, shifting to first gear at 90 mph, or shifting to top gear at 10 mph.
In addition, if the driver does not shift up, the next gear will be automatically selected when the engine revolutions reach approximately 6000 rpm. Equally, if the driver does not shift down when reducing vehicle speed, the system performs the down-change automatically thus ensuring the transmission is in the appropriate gear when throttle is applied. This prevents excessive clutch slip should the throttle pedal be reapplied.
Driving and ambient conditions can influence the pulley positions, these conditions include
- Oil temperature
- Clutch slip
- Hydraulic balancing of the controlling cylinders
- Hydraulic pressure within the control lines
The primary and secondary pulleys alter their position to maintain the commanded transmission input/output ratio.
All inputs and outputs of the ECVT control system pass through the EMS 2000 and the GIU The EMS 2000 monitors the speed of the transmission output shaft and communicates with the GIU to select the correct gear ratio to suit the current driving conditions. The GIU drives the park, reverse, neutral, drive and sport LED module to display the selected gear next to the gear selector lever and the EMS drives the instrument cluster display.
Scheme 261
Drive Mode
In the ECVT modes, the control system operates by deriving a target engine speed based on current vehicle speed and driver demand. In manual mode, the system derives a target engine speed based on the vehicle speed and the current gear ratio. Having obtained an engine speed target, the system calculates the appropriate ratio control motor position and instructs the GIU to deliver this position.
The engine load calculation will depend on two factors
- The vehicles road speed.
- The driver's demand (throttle position).
The EMS 2000 also needs to control the speed of the ratio control motor in order to protect the transmission from damage due to drive belt slippage. This is more likely to occur at low transmission oil temperatures, and when the transmission is delivering a large change in ratio (for example, after a manual gear change, or sudden throttle movement in Drive mode).
Four speeds are used by the Ratio Control Motor. The motor is accelerated as appropriate to ensure the motor does not lose its reference, thereby compromising system control.
The EMS 2000 also knows the maximum torque that the belt can transfer across all possible ratio ranges. It is extremely important that the belt is not allowed to slip on the pulleys, as this would cause excessive wear.
Target Engine Speed
The target engine speed is critical in deciding the position of the ratio control motor. The EMS 2000 will keep changing the ratio of the motor to achieve the target engine speed. The target engine speed is mapped inside the EMS 2000 against Road speed and Driver demand (throttle angle).
The map is not linear. To achieve good driving characteristics the engine target speed map is programmed to overcome.
- The initial engine speed required to build pressure within the hydraulic clutch.
- The hydraulic profile of the transmission itself.
- The engines power and torque profile.
When the transmission is operating in the D mode (drive), the driver does not experience full engine power until the road speed reaches 50 mph.
Sports Mode
The EMS 2000 uses the same map programmed into the EMS 2000 as it uses for normal Drive mode but applies a scalar function to the throttle angle. For example if the driver selects sports mode and has the throttle applied by 40%, the scalar function will be applied so that the EMS 2000 uses a throttle angle of 60% to calculate its target engine speed. The instrument cluster display will change from 'D' to 'SD'.
Manual Mode
As soon as the EMS 2000 receives one of the "+ or -" switched inputs via the GIU, the EMS 2000 stops displaying 'S', and changes to one of six gear position displays.
Fault Mode
When the EMS 2000 or GIU detects a fault, the EMS 2000 will try to position the ratio control motor so that the engine speed in most driving conditions is around 2800-3200 rpm. In this position the vehicle still has reasonable driving characteristics. For certain failure modes, where the EMS 2000 cannot command the position of the motor, the GIU will set the motor position to 130 steps (full range of travel is 0-214 steps). In this case, the engine speed in most driving conditions will be 3750-4000 rpm.
The EMS 2000 will instruct the instrument cluster to display 'EP', or the Engine MIL depending on legislative requirements. There are certain faults that when stored will not cause the EMS 2000 to default the transmission into its limp home position.
These are
- Gear lever + switch failure.
- Gear lever - failure.
- Steering wheel + switch failure (if fitted).
- Steering wheel - switch failure (if fitted).
- Shift interlock system fault.
- Center Console LED fault.
A gearbox default is not necessary for these failures because the control of the gearbox is not compromised; it is only necessary to warn the driver. The EMS 2000 will not operate the sequential gear changes in manual mode if these switches are faulty.
Transmission Adaptation
Due to manufacturing tolerances in the transmission, and since the ECVT system is subject to many strict legislative requirements, it is essential to put the control system through a learning procedure, before the transmission can be controlled effectively.
The 'learn' mode can be recognized because the LCD gear display will display an 'X' character in addition to the current drive mode. The 'X' stands for fast adaptation - the control system is being adapted to adjust its control thus optimizing the performance of the transmission within the particular vehicle. If the transmission or EMS 2000 is changed, the fast adaptation procedure must be repeated. There are two procedures that must be completed before the XP on the display is removed.
Clutch Adaptation
A dealer diagnostic procedure has been written for this function. It is essential that this procedure be followed for a reliable clutch adaptation. Follow the instructions given by the procedure. Having completed the instructions, the ratio adaptation drive cycle can be completed.
Ratio Adaptation
The transmission hydraulic/mechanical characteristics can be mapped inside the EMS 2000. The curve of the input shaft speed verses output shaft speed looks like a straight line up to approximately 2,500 rpm. It then plateau's before rising in a curved manner. This profile will be a similar shape for all transmissions but its position plotted against engine speed will vary.
The EMS 2000 knows the shape of the profile and monitors the actual engine speed relative to the mapped engine speed. The EMS 2000 learns, through historical control, a new profile that is more representative of the actual transmission characteristics. The EMS 2000 also monitors the amount this line moves from the mapped line, as long as this difference is within its tolerance band, the EMS 2000 accepts the value and learns from it. If the actual value goes beyond the adaptive tolerance the EMS 2000 will perform a reset. If the value still exceeds the adaptive tolerance band, the EMS 2000 will store a fault code and place the transmission into its default position.
The figures quoted are only representative, due to the nature of the adaptation, these may or may not be correct. When setting the fast adaptation, the control system will initially target 5,000 rpm in order to learn the ratio control motor position at this engine speed. Once the vehicles power train is stable enough for an adaptation to take place, the ratio control motor position is noted and the control system will target 4,500 rpm. This process continues subsequently targeting 4,000, 3,500, 3,000, 2,500, 2,000, 1,900, 1,800, 1,700, 1,600, 1,500, 1,400. When the 1,400 rpm point has been adapted, normal operation will commence.
To set the fast adaptation procedure drive the car, on a level road, at around 60 km/h in ECVT drive mode, and then lift off the throttle.
As the vehicle decelerates (do not use the brakes) the adaptations will occur. If the vehicle speed drops too far before the process is complete, the engine speed will drop from its targeted speed back towards idle. The instrument cluster display will continue to display the "X" character, and the transmission will not operate normally. If this happens, simply repeat the process by accelerating back to 60 km/h and lift off the throttle again to give the software a chance of learning the remaining points. When the procedure is complete, the display will return to normal.
On the completion of a fast adaptation, the lifetime adaptation strategy will commence, fine tuning the response of the control system for the transmission attached to a particular vehicle.
If either the EMS 2000 or transmission is changed during the service life of the vehicle, the fast adaptation strategies must be reset, which in turn will reset the lifetime strategy so it starts learning from the new base point.
Notes
Service Information
At present replacement is limited to
- Drain and refill
- Inhibitor switch and 'O' ring
- Selector shaft oil seal
- Input shaft and drive shaft oil seals
- Primary cover
- Secondary cover 'O' rings
- Sump gasket
- Oil cooler pipe and unions
Note. All service repair and replacement procedures should be carried out in accordance with the workshop manual.