Electronic Component Description

Electronic Component Description

Transaxle Inputs

Stop Lamp Switch
The stop lamp switch operates vehicle stop lamps and sends signals to the powertrain control module (PCM). The switch is normally open when the brake pedal is in the released position. When the brake pedal is depressed, the switch is closed. If the torque converter clutch (TCC) is engaged when the brake pedal is depressed, the PCM will disengage the TCC.

Transmission Fluid Temperature (TFT) Sensor





The TFT sensor is a thermistor that provides transaxle fluid temperature to the PCM. It is located at the lower transmission case housing. The internal resistance of the sensor varies in relation to the operating temperature of the transaxle fluid. The TFT sensor outputs high voltage at low fluid temperature, and low voltage at high fluid temperature.

Input Speed Sensor (ISS)





The ISS is attached to the outside of the transmission case housing. The ISS generates a signal according to the speed of the mainshaft idler gear on the mainshaft. The PCM receives those signals and determines the speed of the mainshaft.

Output Speed Sensor (OSS)





The OSS is attached to the outside of the transmission case housing. The OSS generates a signal according to the speed of the park gear on the output shaft. The PCM receives those signals and determines the speed of the mainshaft.

Park/Neutral Position (PNP) Switch





The PNP switch is on the backside near the top of the transaxle case housing. Six switches internal to the PNP switch are used to create a signal to the PCM indicating gear selection. The signal of the PNP switch can be viewed on the Scan tool.

Transaxle Outputs

Torque Converter Clutch (TCC) Solenoid





TCC solenoid is a normally closed solenoid used to control the apply and release of the TCC. The TCC solenoid controls hydraulic pressure from the modulator valve to the lock-up shift valve depending on the PCM command.

When the PCM activates the torque converter lock-up, it commands the TCC solenoid OFF, and hydraulic pressure is sent to the TCC solenoid. When the PCM de-activates the torque converter lock-up, it command the TCC solenoid ON, and the hydraulic pressure is exhausted.

Shift Solenoid A, B, C





The automatic transmission (AT) clutch pressure control (CPC) solenoid and the TCC lock-up pressure control solenoid are normally a closed solenoid used to control hydraulic pressure from the modulator to the CPC valves and the TCC Lock-Up pressure control solenoid respectively.

CPC Solenoid Valve A, B and TCC Lock-Up Pressure Control Solenoid





The CPC solenoid valves are used to control hydraulic fluid pressure during shifting. A spool in the CPC solenoid valve assembly pushes a valve according to the duty cycle, which is controlled by the PCM, and controlled fluid pressure is then supplied to various valves.

The PCM measures the current amperage flowing through the CPC solenoid valve and uses feedback control to compensate the difference between the actual current amperage and the commanded one.

3rd Clutch Oil Pressure Switch





The 3rd clutch oil pressure switch is used to detect fluid pressure applied to the 3rd clutch. The 3rd clutch oil pressure switch sends a signal to the PCM.

4th Clutch Oil Pressure Switch





The 4th clutch pressure switch is used to detect fluid pressure applied to the 4th clutch. The 4th clutch pressure switch sends a signal to the PCM.