General

For vehicles equipped with a manual transmission, cruise control can only be activated when the Cruise Control Switch (X115) is depressed, the transfer gear box is in Hi range, and the clutch pedal is not depressed. Also, the BeCM (Z238) will deactivate cruise control if the engine rpm rises above 5000 +/- 10%, due to the possibility of selecting gears manually without the use of the clutch.

For vehicles equipped with an automatic transmission, cruise control can only be activated when the Cruise Control Switch (X115) is depressed, the transfer gear box is in Hi range, and the transmission is in one of the forward gears. With the Cruise Control Switch (X115) on, a ground signal is applied to C255/Pin 14 of the BeCM (Z238). The transfer gear box Hi range status from the Transfer Gear Box ECU (Z256) is applied to C626/Pin 3 of the BeCM (Z238). The X, Y, and Z switch status (PRND321 position information) from the gearbox position switch is applied to C626/Pins 8, 9, and 18 of the BeCM (Z238). The clutch pedal position input is applied to C255/Pin 4 and the engine speed input is applied to C112/Pin 9 of the BeCM (Z238). The BeCM (Z238) then supplies voltage, via its Pin 18 to the Inverter/Converter (Z249), to the Cruise Control ECU (Z121), which then knows" that cruise control can be operated, and to the "Operation" bulb of the Cruise Control Switch (X115).

When cruise control is activated and a cruise speed is set, the Cruise Control ECU (Z121) applies voltage through the OU wire and ground through the OR wire to operate the Cruise Control Vacuum Pump (M103) motor. The Cruise Control ECU (Z121) applies ground through the OK wire to close the normally open solenoid valve in the pump. The pump applies vacuum to the actuator.