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 only operates for approximately 15 minutes.

Power is supplied at all times
- through 15 A fuse (Nos. 46 and 47, located in the IPDM E/R)
- to rear window defogger relay
- through 50 A fusible link [letter g, located in the fuse block (J/B)]
- to BCM terminal 70.
- through 15 A fuse [No. 43 (with heated mirrors), located in the IPDM E/R]
- to heated mirror relay.

With the ignition switch turned to ON or START position,

Power is supplied
- through ignition relay
- to rear window defogger relay (located in the IPDM E/R)
- through 10 A fuse [No. 1, located in the fuse block (J/B)]
- to BCM terminal 38
- through 10 A fuse [No. 8, located in the fuse block (J/B)]
- to front air control terminal 6.

Ground is supplied
- to BCM terminal 67
- to front air control terminal 20
- 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 20
- 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 via CAN communication (CAN-H, CAN-L).

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 and then rear window defogger relay is energized.

With power and ground supplied, rear window defogger filaments heat and defog the rear window.

When rear window defogger relay is turned to ON, (with heated mirrors)

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 1.

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 mirror.

CAN Communication System Description
Refer to Information Bus.