REAR WINDOW DEFOGGER SYSTEM

System Diagram

Operation Description

Turn rear window defogger switch ON when the ignition switch is turned ON. Then multifunction switch (rear window defogger switch) transmits rear window defogger switch signal to AV control unit via AV communication. AV control unit transmits rear window defogger switch signal to BCM via CAN communication.
BCM turns rear window defogger relay ON and transmits rear window defogger control signal to IPDM E/R via CAN communication when rear window defogger switch signal is received.
Rear window defogger and door mirror defogger (with mirror defogger) are supplied with power and operate when rear window defogger relay turns ON.
IPDM E/R transmits rear window defogger control signal to AV control unit via CAN communication.
AV control unit transmit rear defogger indicator signal to multifunction switch (rear window defogger switch) via AV communication then rear window defogger indicator is illuminated.

Timer function

BCM turns rear window defogger relay ON for approximately 15 minutes when rear window defogger switch is turned ON. It makes rear window defogger and door mirror defogger (with 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 turned OFF.

INPUT/OUTPUT SIGNAL CHART

Switch	Input signal to BCM	BCM function	Actuator
Rear window defogger switch	Defogger switch signal	Rear window defogger & Door mirror defogger control	Rear window defogger Door mirror defogger
Push button ignition switch	Ignition signal	Rear window defogger & Door mirror defogger control	Rear window defogger Door mirror defogger

1.	Rear window defogger relay (built-in relay box)	2.	BCM M118, M119, M122, M123	3.	IPDM E/R E6
4.	Rear window defogger switch (built-in multifunction switch M72)	5.	Rear window defogger connector B471	6.	Condenser B33
7.	Rear window defogger connector B472	8.	AV control unit M81, M82
A.	Dash side lower (driver side)	B.	Dash side lower (passenger side)	C.	Engine room dash panel (RH)
D.	Behind rear pillar finisher (LH)	E.	Behind rear pillar finisher (RH)	F.	Behind cluster lid C

Item	Function
BCM	Operates the rear window defogger with the operation of rear window defogger switch. Performs the timer control of rear window defogger.
Rear window defogger relay	Operates the rear window defogger and the door mirror defogger with the control signal from BCM.
IPDM E/R	Transmit rear window defogger control signal to AV control unit via CAN communication.
Multifunction switch (Rear window defogger switch)	The rear window defogger switch is installed. Turns the indicator lamp ON when detecting the operation of rear window defogger.
AV control unit	Displays the rear window defogger ON to the display when detecting the operation of rear window defogger.
Rear window defogger	Heats the heating wire with the power supply from the rear window defogger relay to prevent the rear window from fogging up.
Door mirror defogger	Heats the heating wire with the power supply from the rear window defogger relay to prevent the door mirror from fogging up.