Transaxle Inputs

TRANSAXLE INPUTS
The transaxle controller, located inside the powertrain control module (PCM) receives five signals from various switches and sensors and two signals (vehicle speed and engine rpm), internally from the engine control module, also located within the PCM.

BRAKE SWITCH
The brake switch is a normally closed switch that sends a battery voltage signal to the PCM. If the transaxle is in 2nd gear and engine speed is low, and the brake switch opens signalling the PCM that the brakes are applied, the PCM unlocks the torque converter. This switch helps determine if a downshift should occur while going down a hill.

TRANSAXLE SHIFT MODE SELECTOR SWITCH
A transaxle shift mode selector switch is used on the automatic transaxle to allow the operator of the vehicle to select a normal or performance (aggressive) shift schedule. The switch is located on the console near the gear select lever.

Initial shifts after a cold start are completed in normal mode even if the performance mode is selected. Performance shift schedule timing and pressures are based on learned normal mode shift characteristics.

The Norm/Perf switch is a simple On/Off switch. The PCM supplies a 12 volt signal to the Perf/Norm switch. When Perf mode is selected, the PCM circuit will be pulled to ground. When the switch is in Norm mode, the circuit is opened and the PCM pin will be at battery voltage.

TRANSAXLE FLUID TEMPERATURE SENSOR
The transaxle fluid temperature sensor is a thermistor-type sensor located in a transaxle pressure port, near the pressure filter. Sensor resistance increases as temperature decreases, and decreases as the temperature increases. The PCM supplies a five volt signal to the sensor on circuit 585. The PCM monitors the voltage signal as it varies up and down with circuit resistance. The voltage value on the signal line is converted to a temperature value internally by the PCM.

TRANSAXLE TURBINE SPEED SENSOR
The transaxle turbine speed sensor is a permanent magnet (PM)generator mounted near the pressure filter on the transaxle case. The sensor produces a pulsing voltage whenever turbine shaft speed is above 250 rpm. These pulses occur eight times per each turbine shaft revolution and are translated to provide turbine shaft speed in rpm.

TRANSAXLE GEAR SELECTOR SWITCH
The transaxle gear selector switch contains four switches that ground four different circuits. These circuits are 771 (switch A), 772 (switch B), 773 (switch C) and 776 (switch D). (The transaxle gear selector switch also contains the backup lamp switch and the neutral/start switch.)

The transaxle monitors these four circuits and determines what gear the operator has selected by the combinations of opens and grounds. Each combination indicates a specific selection in the manual shift quadrant (PRND32).

Refer to the chart for selector switch, transaxle gear select position for further information.

POWERTRAIN CONTROL MODULE (PCM) INPUTS
The engine controller (EC) located in the powertrain control module (PCM) shares two signals with the transaxle controller (TC). These two signals are the vehicle speed signal (received from the vehicle speed sensor), and an ignition voltage signal.

The vehicle speed signal is used by the transaxle control module to determine vehicle speed for transaxle shifting.

The ignition voltage signal is the turn On signal for the transaxle control module.