System Description

SYSTEM DIAGRAM

Courtesy of NISSAN

Component	Function
A/C auto amp. (with automatic A/C)	A/C auto amp. receives rear window defogger switch signal from A/C switch assembly via LIN communication and transmits rear window defogger request signal to BCM via CAN communication. A/C auto amp. receives rear window defogger feedback signal from BCM via CAN communication and transmits it to A/C switch assembly.
A/C amp. (with manual A/C)	A/C amp. receives rear window defogger switch signal from A/C switch assembly via LIN communication and transmits rear window defogger request signal to BCM via CAN communication. A/C amp. receives rear window defogger feedback signal from BCM via CAN communication and transmits it to A/C switch assembly.
BCM	Receives rear window defogger request signal from A/C auto amp. via CAN communication. Turns ON the rear window defogger relay based on the received signal. Transmits rear window defogger feedback signal to A/C auto amp. via CAN communication. Performs the timer control of rear window defogger and door mirror defogger.
A/C switch assembly (Rear window defogger switch)	Rear window defogger switch is installed. Transmits rear window defogger switch signal to A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), via LIN communication. Receives rear window defogger feedback signal from A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), via LIN communication. Turns the indicator lamp ON when detecting the operation of rear window defogger.
Door mirror defogger	Refer to Component Description .
Rear window defogger	Refer to Component Description .
Rear window defogger relay	Refer to Component Location .
Rear window defogger condenser	Reduce the noise of rear window defogger operation.

SIGNAL TRANSMISSION FUNCTION LIST

Switch	Input signal to BCM	BCM function	Actuator
Rear window defogger switch	Defogger switch signal	Rear window defogger control	Rear window defogger Door mirror defogger (if equipped)

OPERATION DESCRIPTION

Turn rear window defogger switch ON when the engine running. Then A/C switch assembly transmits rear window defogger switch signal to A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), via LIN communication line.
A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), transmits rear window defogger request signal to BCM via CAN communication.
BCM turns rear window defogger relay ON and transmits rear window defogger feedback signal to A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), via CAN communication when rear window defogger request signal is received.
Rear window defogger and door mirror defogger are supplied with power and operate when rear window defogger relay turns ON.
A/C auto amp. (with automatic A/C), or A/C amp. (with manual A/C), transmit rear window defogger feedback signal to A/C switch assembly via LIN communication line when rear window defogger feedback signal is received.
A/C switch assembly turns on the rear window defogger indicator lamp when rear window defogger feedback signal is received.

TIMER FUNCTION

BCM turns rear window defogger relay ON for approximately 20 minutes when rear window defogger switch turns ON. It makes rear window defogger and door mirror defogger operate.
Timer is canceled after pressing rear window defogger switch again during timer operation. Then BCM turns rear window defogger relay OFF. The same reaction also occurs during timer operation, if the ignition switch is placed OFF.