Heated Glass Element: Description and Operation

REAR WINDOW DEFOGGER

System Description
The rear window defogger system is controlled by BCM (body control module) and IPDM E/R (intelligent power distribution module engine room).
The rear window defogger operates only for approximately 15 minutes.
Power is supplied at all times
- through 15 A fuses (No. 46 and 47, located in the IPDM E/R)
- to rear window defogger relay (located in the IPDM E/R)
- through 15 A fuse (No. 43, located in the IPDM E/R) (with heated mirrors)
- to heated mirror relay (located in the IPDM E/R) (with heated mirrors)
- through 50 A fusible link (letter f , located in the fuse and fusible link box)
- to BCM terminal 70.

With the ignition switch turned to ON or START position, power is supplied
- through ignition switch
- to rear window defogger relay (located in the IPDM E/R)
- through 10 A fuse (No. 59, located in the fuse and relay box)
- to BCM terminal 38

With the ignition switch in the ON position, power is supplied
- through 10 A fuse [No. 8, located in the fuse block (J/B)]
- to front air control terminal 14.

Ground is supplied
- to BCM terminal 67
- to front air control terminal 1
- through body grounds M57, M61 and M79
- to IPDM E/R terminals 38 and 59
- through body grounds E9, E15 and E24.

When front air control (rear window defogger switch) is turned to ON, ground is supplied
- to BCM terminal 9
- through front air control terminal 11
- through front air control terminal 1
- through body grounds M57, M61 and M79.

Then rear window defogger switch is illuminated.
Then BCM recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signals to IPDM E/R and display control unit (with navigation) or display unit (without navigation) via CAN communication (CAN-H, CAN-L).
When display control unit (with navigation) or display unit (without navigation) receives rear window defogger switch signals, and is displayed on the screen.
When IPDM E/R receives rear window defogger switch signals, ground is supplied
- to rear window defogger relay (located in the IPDM E/R)
- through IPDM E/R terminals 38 and 59
- through body grounds E9, E15 and E24.

Then, rear window defogger relay is energized.
With power and ground supplied, rear window defogger filaments heat and defog the rear window.
If the rear power drop glass is lowered while the rear window defogger is ON, the rear window defogger will turn OFF. The rear window defogger will turn ON when the rear power drop glass is raised to the closed position if the rear window defogger switch is ON.

When rear window defogger relay is turned to ON, (with door mirror defogger), power is supplied
- through heated mirror relay (located in the IPDM E/R)
- through IPDM E/R terminal 23
- to door mirror defogger (LH and RH) terminal 10 (with automatic drive positioner), terminal 4 (without automatic drive positioner).

Door mirror defogger (LH and RH) is grounded through body grounds M57, M61 and M79.
With power and ground supplied, rear window defogger filaments heat and defog the rear window and door mirror defogger filaments heat and defog the mirrors.

CAN Communication System Description
Refer to "Information Bus".