Set/Accel

To set a cruise speed, the Cruise Control Switch (X115) must be on and vehicle speed must exceed 28 mph (45 km/h). When the SET/ACCEL Switch is depressed under these conditions, the Converter/Inverter (Z249) is supplied with a ground signal. This signal is "converted" to a voltage signal and is transmitted via the SY wire to the Cruise Control ECU (Z121) terminal 3, causing the vacuum pump to operate. When the SET/ACCEL Switch is released, the signal is removed from terminal 3, signalling the ECU to set the speed.