Component Arrangement
Component Arrangement:
Function of individual components
1. Upshift and downshift switches
Installation position: In the steering wheel.
In the manual gate, they connect ground to the Tiptronic control module, which initiates upshifting or downshifting, depending on the speed.
2. DME control module
Mounting location for coupe:
Vehicle interior behind the right-hand spare seat trough.
Mounting location for Cabriolet:
In the convertible top box on the roll-over system frame.
The DME control module is connected with the Tiptronic control module. It transmits the following information via a control line (CAN bus):
Rpm,
torque,
throttle position,
engine temperature.
3. Tiptronic control module
Mounting location for coupe:
Vehicle interior behind the right-hand spare seat trough.
Mounting location for Cabriolet:
In the convertible top box on the roll-over system frame.
The Tiptronic control module is the information and command centre of the entire system. From a large volume of incoming information (measured variables), which are compared with stored driving and shifting programs, the Tiptronic control module selects the characteristic suitable for the type of driving and sends commands to the transmission to shift or not to shift.
4. Coolant changeover valve
Installation position: On the engine (transport eye).
Depending on the ATF and coolant temperature, the changeover valve is activated by the Tiptronic control module and routes vacuum to the shutoff valve, which opens or closes the transmission coolant circuit.
5. Multi-function switch
Installation position: On the transmission.
The multi-function switch is actuated directly by the selector lever via a cable and transfers the selector lever position to the transmission control module. It controls the reversing lights and disables the starter when a transmission range is selected.
The "reduced driving program" is activated if this signal is faulty.
6. Solenoid valves (SV)
Installation position: On the hydraulic control unit in the transmission.
The electronic transmission controls the transmission functions via the SVs. SVs 1, 2 and 3 are On-Off valves. Their task is to switch over valves in the hydraulic system.
The SVs (pressure regulators 1 ... 4) are electronic pressure control valves. They convert an electric current into a proportional hydraulic pressure, and actuate the valves of the shifting elements.
7. Sender for ATF temperature
Installation position: The sender is integrated in the transmission wiring harness. If it is damaged, the entire wiring harness must be replaced.
The sender controls the modulation pressure of the transmission in accordance with the ATF temperature. This keeps shifting operations very comfortable across the entire temperature range.
It the ATF temperature is too high, the control module selects a map with the least power loss possible and closes the torque converter clutch. In addition, downshifting takes place at higher engine speed values. This reduces converter slip, and the ATF can cool down.
The sender is regarded as defective if the signal voltage exceeds or falls below the prescribed signal voltage range. Shifting then takes place with a substitute value of 80 °C.
8. Sender for transmission input speed
Installation position: On the hydraulic control unit in the transmission.
The sender (inductive pickup) transfers the transmission input speed to the transmission control module.
9. Sender for transmission speed
Installation position: Beside the hydraulic control unit in the transmission.
The sender (inductive pickup) transfers the transmission speed (output speed) to the transmission control module.
The controller calculates the speed from the output speed of the transmission.
10. ABS control module
Installation position: In the front luggage compartment.
The ABS control module is connected with the Tiptronic control module. It transfers the front wheel speeds, which are required for slip monitoring and for calculation of the transverse acceleration.
Furthermore, on vehicles with traction control (TC), the Tiptronic control module is signalled whether TC is active. The Tiptronic control module goes to a special map when this information is received.
11. Stop light switch
Installation position: In front of the brake pedal.
The transmission control module requires the stop light switch signal in order to initiate downshifting before curves and for activation of the shiftlock lift solenoid.
12. Kick-down switch
Installation position: In the accelerator pedal box in front of the accelerator.
NOTE: As the accelerator pedal box must not be opened, the complete accelerator pedal box must be replaced if the kick-down switch is defective.
The kickdown switch detects when the accelerator pedal is floored past the full-throttle position. It connects ground to the Tiptronic control module, which shifts the shifting times for faster acceleration. The transmission shifts down immediately, depending on the engine speed, and shifts up again only when the highest permissible engine speed is reached.
Kick-down is not performed if the switch is defective.
13. Selector lever with manual switch
The selector lever transmits the selector lever positions to the transmission and the multifunction switch via a cable.
In the manual gate the manual switch connects ground to the Tiptronic control module which enables manual tip shifting.
14. Instrument cluster
The respective selector lever position and the engaged gear are displayed in the instrument cluster.
In the "Reduced driving program", the position display flashes alternately with the 4th gear.