Nissan Altima (L32) 2007-2012 Service Manual: Rear window defogger system

System Diagram

System Description

Operation Description

• Turn rear window defogger switch ON when the ignition switch is turned ON. Then front air control (rear window defogger switch) transmits rear window defogger switch signal to BCM.

• BCM turns rear window defogger relay ON when rear window defogger switch signal is received.

• Rear window defogger and door mirror defogger (with door mirror defogger) are supplied with power and operate when rear window defogger relay turns ON.

• BCM transmits rear window defogger control signal to IPDM E/R via CAN communication when rear window defogger operates.

• Rear window defogger ON is displayed when front air control receives signals.

Timer function

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

INPUT/OUTPUT SIGNAL CHART

*: With door mirror defogger

Component Parts Location

1. BCM M16, M17, M18, M19 (view with instrument panel removed)

2. IPDM E/R E17

3. A. Fuse block (J/B) B. Rear window defogger relay J-4

4. Front air control (rear window defogger switch) M37

5. Door mirror (door mirror defogger) LH D4, RH D107 (if equipped)

6. A. Rear window defogger (+) B53 B. Condenser B52 (view with rear pillar finisher LH removed)

7. Rear window defogger (-) B54 (view with rear pillar finisher RH removed)

Component Description

*: With heated mirrors