Pickup 2WD V6-180.5 2959cc 3.0L SOHC (3VZ-E) (1989)
Voltage Signal: Description and Operation
ECU Input Switches
AIR CONDITIONER SWITCH
When the A/C is turned on, the ECU monitors the signal from the compressor clutch. The ECU uses this signal for controlling idle speed during A/C
operation. The A/C switch inputs the ECU through terminal A/C.
BRAKE LIGHT SWITCH
The Brake Light Switch is used to detect when the vehicle is braking. This signal is sent to the ECU to reduce fuel delivery on deceleration. The
signal inputs the ECU through terminal STP.
FOURWHEEL DRIVE SWITCH
This switch signals the ECU when the transfer case has been shifted into fourwheel drive operation. The ECU uses this information to override certain
operating functions for improved low rpm/high torque off-road driving. The 4WD Switch inputs the ECU through terminal 4WD.
NEUTRAL START SWITCH
This switch is installed on A/T models to inform the ECU of transmission gear selection. This information is used by the ECU to control starter
operation and engine idle operation. The signal inputs the ECU through terminal NSW.
TPS (IDL) SWITCH
The ECU senses whether the throttle valve is open or closed by a switch in the Throttle Position Sensor (TPS). The ECU uses this information to
control fuel delivery at idle and on deceleration. This signal inputs the ECU through terminal IDL.