Design

Design

Control module/gear-shift position sensor




The transmission control module (TCM) and the gear-shift position sensor form one unit. This unit is mounted on the top of the transmission housing, on the gear shift linkage rod. The control module connector is directly connected to the transmission.
The gear-shift position sensor provides the transmission control module (TCM) with information about the gear selected and whether back-up (reverse) gear is selected so that the back-up (reversing) lamps can be lit if required. The gear-shift position sensor contains a permanent magnet and a linear Hall sensor. The gear-shift position sensor generates a signal voltage between 0 and 5 V. This signal voltage corresponds to the currently selected gear selector lever position.
There are diagnostics for the gear-shift position sensor.
Voltage level for the different gears
P approximately 0.65 V
R approximately 1.64 V
N approximately 2.12 V
D approximately 2.49 V

Shift solenoids S1, S2, S3, S4 and S5




The shift solenoids S1, S2, S3, S4 and S5 are positioned in the valve body in the transmission control system, which is mounted on the front edge of the transmission. The shift solenoids (on/off type), consist of an electrical coil which controls a hydraulic valve. The solenoids are supplied with 12 V via the transmission control module (TCM) and grounded in the control system. The shift solenoids control shifting. The transmission control module (TCM) determines which gear is to be used by activating them in different patterns.
There is a diagnostic for the shift solenoids.

Lock-up-solenoid, SLU




The lock-up-solenoid, SLU is located in the gearbox control system, which is mounted on the front edge of the gearbox.
The lock-up-solenoid, SLU consists of an electric coil that controls a hydraulic valve. The solenoid is controlled, like all linear solenoids in the gearbox, by a pulsed (PWM) current with a frequency of 300Hz and grounded via the Transmission Control Module (TCM). The average value on the current signal that deploys the solenoid varies between 0.1 A and 1 A and the demand controls the deployment.
The solenoid controls the torque converter's Lock-up engagement. Engagement occurs by the solenoid pulsing, which gives a smooth engagement of the lock-up function. The solenoid allows the torque converter to work in one of three positions: "Open", "Controlled slipping" and "Locked".
The hydraulic function of the solenoid is linear.
There are diagnostics for the solenoid.

Linear solenoid, SLS




The line pressure solenoid, SLS is in the transmission control system, which is mounted on the front edge of the transmission. The line pressure solenoid, SLS consists of an electrical coil which controls a hydraulic valve. The solenoid is controlled by pulse width modulation (PWM) voltage. The solenoid is grounded via the transmission control module (TCM). The hydraulic function of the solenoid is linear. The hydraulic valve is controlled by the varied current which is the result of the pulse conditions. During high pulse conditions, (at high currents (approximately 1 A)) the line pressure is low. During low pulse conditions (at low currents) the line pressure is high. In the event of an open-circuit the line pressure reaches maximum which causes hard shifting. The hydraulic valve is then completely open.
There are diagnostics for the solenoid.

Linear solenoid, SLT




The line pressure solenoid, SLT is in the transmission control system, which is mounted on the front edge of the transmission. The line pressure solenoid, SLT consists of an electrical coil which controls a hydraulic valve. The solenoid is controlled by pulse width modulation (PWM) voltage. The solenoid is grounded via the transmission control module (TCM). The hydraulic function of the solenoid is linear. The hydraulic valve is controlled by the varied current which is the result of the pulse conditions. During high pulse conditions, (at high currents (approximately 1 A)) the line pressure is low. During low pulse conditions (at low currents) the line pressure is high. In the event of an open-circuit the line pressure reaches maximum which causes hard shifting. The hydraulic valve is then completely open.
There are diagnostics for the solenoid.

Transmission input speed sensor (speed of the input shaft)




The transmission input speed sensor (input shaft speed ) is on the upper side of the transmission housing. The sensor is an active sensor and is supplied with 12 V. When the pulse wheel on clutch C1 rotates, the sensor generates a pulsed current (quadratic wave) where the strength of the current depends on the position of the pulse wheel. The signals from the coil in the sensor are then effected by a magnetic resistance element, which generates a current which oscillates between 7 mA and 14 mA, and the frequency of which increase with speed. The transmission control module (TCM) calculates the transmission input speed using the signal from the sensor.
The transmission control module (TCM) uses information about the input shaft speed to calculate the torque reduction to be requested from the engine control module (ECM) when shifting. The value is also used to compare the engine speed (RPM) with the speed of the input shaft in order to calculate the slipping rate of the torque converter. The value is also compared with the transmission output speed sensor signal in order to calculate the actual gear ratio. This is done to check whether the value corresponds to the expected gear ratio.
There are diagnostics for the transmission input speed sensor.

Transmission output speed sensor (speed of the output shaft)




The transmission output speed sensor (speed of the output shaft) is on the reverse of the transmission housing. The sensor provides signals to the transmission control module (TCM) about the vehicle speed. The output shaft speed sensor is an active sensor and is supplied with 12 V. When the pulse wheel (wheel for shift-lock) rotates, the sensor generates a pulsed current (quadratic wave) where the strength of the current depends on the position of the pulse wheel. The signals from the coil in the sensor are then effected by a magnetic resistance element, which generates a current which oscillates between 7 mA and 14 mA, and the frequency of which increase with speed. The control module calculates the transmission output speed using the signals from the sensor. The signal is compared with the signal from the transmission input speed sensor and is used to calculate the gear ratio and is also used for diagnostics.
There are diagnostics for the transmission output speed sensor.

Oil temperature sensor




The temperature sensor is an NTC sensor. The temperature sensor is on the transmission control system inside the side cover. It gauges the temperature of the transmission fluid in the oil pan. The temperature sensor is integrated in the cable harness. The temperature sensor is supplied with 5 V and is grounded via the transmission control module (TCM). The control module can determine the transmission fluid temperature by measuring the voltage drop across the NTC resistor of the sensor. The control module stores the time the temperature has been within a certain temperature range. If a certain temperature and time has been exceeded, a diagnostic trouble code (DTC) indicating that a oil change is necessary is stored.
There are diagnostics for the temperature sensor.

Gear selector module (GSM)




The gear selector assembly is in the tunnel console. It is mechanically connected to the transmission by a cable which moves the gear valve in the transmission control system. The gear selector module (GSM) is on the top panel of the gear selector assembly. The gear selector module (GSM) is powered by the transmission control module (TCM). The gear selector module (GSM) uses serial communication to communicate with the transmission control module (TCM) to light the gear position indicator for example. The gear selected is indicated by a row of LEDs in the top panel on the gear selector assembly.
There is a directly connected cable from the transmission control module (TCM) to the gear selector module (GSM) which controls the shift-lock solenoid. The power supply and ground for the shift-lock solenoid are directly connected to the gear selector module (GSM).
The switch for winter mode (W) is located in the lever carrier's top panel (switch and function are discontinued from model year 2008). At activation, the switch sends a request to activate winter mode to Transmission control module (TCM) (TCM). Transmission control module (TCM) then decides if winter mode is possible or not.
There are diagnostics for the gear selector module (GSM). In the event of a fault, a signal about the fault status is transmitted to the transmission control module (TCM) where any diagnostic trouble codes (DTCs) are stored.

Gear selector assembly

Gear selector assembly with Geartronic function




Gear selector assemblies with Geartronic are unique in appearance and function. In addition to P/R/N/D modes they also have a "manual" (M) shifting mode.
The gear selector for Geartronic has the following functions:
- P: Park position
- R: Back-up (reverse).
- N: Neutral.
- D: Automatic shifting between all gears. (Does not apply when the mode selector is in winter mode (W), for further information see, Function/Shifting program/(Winter mode))
- M: Manual shifting. There are three Hall sensors on the gear selector module (GSM). A permanent magnet on the cover in the gear selector lever affects the output signals of the Hall sensors to the gear selector module (GSM).