Control Systems
Overview
| 1. Solenoid SL5 | 6. Solenoid S2 |
| 2. Solenoid SL4 | 7. Solenoid SL2 |
| 3. Solenoid S1 | 8. Solenoid SL3 |
| 4. Solenoid SL1 | 9. Solenoid SLT |
| 5. Solenoid SLU | 10. EMOP (Electro Magnetic Oil Pump) |
Wiring
From the gearbox connector, the cables in the gearbox are divided into three wiring harnesses for the following components:
- EMOP
- The solenoids, SL1-SL5, SL1, SL2, SLT and SLU.
- Oil temperature sensor
- Speed sensor input speed
- Speed sensor output speed
Linear pressure solenoids SL1-SL5
- SL1 steplessly controls the actuation of clutch C1.
- SL2 steplessly controls the actuation of clutch C2.
- SL3 steplessly controls the actuation of clutch C3.
- SL4 steplessly controls the actuation of clutch C4.
- SL5 steplessly controls the application of brake B1.
Solenoid position is controlled by TCM by means of a PWM signal. De-energized, the valve is closed.
In the event of a fault in the pressure regulation to a clutch or brake, the voltage feed to the failed solenoid is disconnected. The result is that the gearbox enters Emergency Mode with changed gear change pattern.
The gear change pattern differs depending on the nature of the fault.
Solenoids S1 and S2
Solenoids S1 and S2 are fitted in the gearbox control system. The solenoids are the On/Off type and consist of an electrical coil that controls a hydraulic valve.
TCM supplies 12V voltage to the solenoids. Solenoid S1 controls certain gear changes and solenoid S2 is used, amongst other things, during engine braking for 1st gear.
The solenoids S1 and S2 hydraulically control the position of the valves in the control system, which in turn control the oil flow to the linear pressure solenoids (SL1-SL5) that are being used at the time.
De-energized, the valve is closed.
Solenoid position is controlled by TCM by means of a PWM signal. De-energized, the valve is closed. In the event of a malfunction, the voltage feed to the solenoid with no lock-up function is disconnected as a result.
Line pressure solenoid SLT
Depending on accelerator position and engine torque, the solenoid steplessly (linearly) controls gearbox system pressure.
Solenoid position is controlled by TCM by means of a PWM signal.
At high current intensity (approx. 1A) the system pressure is low (valve closed), and at low current intensity the system pressure becomes high.
De-energized, the valve is open. When a fault is detected in the function, the result may be that the voltage feed to the solenoid is disconnected. This means that the system pressure is maximized, with hard gear changes as a result.
Lock-up solenoid SLU
The solenoid steplessly controls the position of the valve and thereby the lock-up function's degree of application, based on the position of the accelerator pedal, the engine speed and the input and output speed of the gearbox.
Solenoid position is controlled by TCM by means of a PWM signal. De-energized, the valve is closed.
In the event of a malfunction, the voltage feed to the solenoid with no lock-up function is disconnected as a result.
EMOP (Electro Magnetic Oil Pump)
EMOP is an oil pump (displacement pump) controlled by the TCM by means of frequency modulation. The pump is used to actuate clutch C1 when the engine is switched off for Start/Stop.
In terms of function, EMOP replaces the solenoid SL1 for Start/Stop when the engine is switched off.
By actuating clutch C1, gear 1 is ready when the engine is started again.
De-energized, the valve is closed.
Temperature sensor transmission oil
The temperature sensor for transmission oil is connected to TCM and is included as part of the cable harness.
TCM uses the oil temperature as one of the parameters in order to, amongst other things, calculate:
- Gearbox shift points
- Engagement and disengagement of the lock-up function
- The torque converter's temperature. If the temperature is too high, a diagnostic trouble code is generated and engine torque is limited.
The oil temperature sensor is an NTC sensor.
Integrated position sensor
The sensor informs TCM of gear selector position. It also informs whether reverse gear is engaged so that the reversing lamps are switched on.
The sensor contains a permanent magnet and a linear hall sensor. The sensor creates a signal voltage between 0 and 5V depending on gear selector position.
| Gear shift position | Voltage level |
| P | 0.65 V |
| R | 1.64 V |
| N | 2.12 V |
| D | 2.49 V |
Wheel speed sensor
The gearbox has a speed sensor for input speed, and a speed sensor for output speed. The sensors are hall sensors and are fitted inside the gearbox.
The sensor for the input shaft is actuated by the toothed wheel on the clutch drum for clutch C2.
The sensor for the output shaft is actuated by the intermediate shaft's gear, which transmits the power to the differential.
The sensors generate a square wave pulse where the frequency increases with speed.