Sonata V6-3.0L (1991)
System Relay: Description and Operation
Air Conditioner Relay Location
Air Conditioner Control System
When the air conditioner switch is turned on, while the engine is at idle, the Idle Speed Control (ISC) servo operates to increase the engine speed.
However, there is some delay before the engine speed actually increases. To maintain the engine free from the air conditioner load during that delay
period, the ECU keeps the power transistor off for about 0.5 seconds to open the air conditioner power relay circuit. As a result, even if the air
conditioner switch is on, the air compressor is not driven instantly, preventing engine speed drop due to compressor load. In addition, for automatic
transmission equipped models, during acceleration when the throttle valve opening is above 65°, the air conditioner power relay circuit is shut off for
approximately five seconds, to enhance acceleration performance.
