Engine Control Module: Locations
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
Installation position: In the passenger compartment behind the right-hand emergency seat recess.
The DME control module is connected to the Tiptronic control module. It transmits following information via a control line (CAN
Rpm,
torque,
throttle position,
engine temperature.
3. Tiptronic control module
Installation position: In the passenger compartment behind the right-hand emergency seat recess.
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 transmits the selector lever position to the transmission control module. It controls the reversing lights and disables the starter when a transmission range is selected.
A defective signal results in "Reduced driving program".
6. Solenoid valves (SV)
Installation position: On the hydraulic control unit in the transmission.
The electronic transmission controls the transmission functions via the SVs. SV s 1, 2 and 3 are On-Off valves. Their task is to switch over valves in the hydraulic system.
The SV s (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. Sensor for ATF temperature
Installation position: The sensor is integrated in the transmission wiring harness. If it is damaged, the entire wiring harness must be replaced.
The sensor 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 speeds. This reduces converter slip, and the ATF can cool down.
The sensor 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 degrees C.
8. Sensor for transmission input speed
Installation position: On the hydraulic control unit in the transmission.
The sensor (inductive pickup) transmits the transmission input speed to the transmission control module.
9. Sensor for transmission speed
Installation position: Beside the hydraulic control unit in the transmission.
The sensor (inductive pickup) transmits the transmission speed (output speed) to the transmission control module.
The control module callates the vehicle speed from the transmission output speed.
10. ABS control module
Installation position: In the front luggage compartment.
The ABS control module is connected to 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. Brake light switch
Installation position: In front of the brake pedal.
The transmission control module needs the signal from the brake light switch in order to trigger downshifting before bends and to actuate the shiftlock solenoid.
12. Kick-down switch
Installation position: In the accelerator pedal box in front of the accelerator pedal.
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 kick-down 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 multi-function 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 and 4th gear flash alternately.