Chart No. 5, Vacuum Pump Drive Circuit Test

Hold Mode. When the Set switch is pushed (ON) and the Cruise switch is ON, and vehicle speed is above the threshold speed, the control unit receives a SET signal and turns the cruise vacuum pump motor ON. After set speed is reached, the motor, control valve and release valve are repeatedly turned ON and OFF according to driving conditions.
Acceleration Mode. When the Resume switch is pressed, the control unit receives a Resume signal and turns ON the cruise vacuum pump motor, control valve and release valve.
Deceleration Mode. When the Set switch in held depressed, the control unit receives a set signal and turns the cruise vacuum pump and control valve Off and turns the release valve On.
Release Mode. When the Set switch is turned OFF, the control unit receives a cancel signal and turns OFF the cruise vacuum pump motor, control valve and release valve.
Measure voltage at vacuum pump drive and control valve open/close outputs, terminal No. 26 then at terminal No. 13. Voltage should measure 12 volts or 0 volts during the Hold mode, 0 volts during the Acceleration mode and 12 volts during both the Deceleration and Release modes.
Measure voltage at release valve open/close output, terminal No. 12. Voltage should measure 12 volts or 0 volts during the Hold mode, 0 volts during both the Acceleration and Deceleration modes and 12 volts during the Release mode.