Heated Glass Element: Description and Operation

REAR WINDOW DEFOGGER

System Description
The rear window defogger system is controlled by BCM and IPDM E/R. The rear window defogger operates only for approximately 15 minutes. Power is at all times supplied
- through 20 A fuse [No. 75, located in the IPDM E/R]
- to rear window defogger relay terminals 6,
- through 20 A fuse [No. 80, located in the IPDM E/R]
- to rear window defogger relay terminals 3,
- through 15 A fuse [No. 37, located in the fuse and fusible link box
- to multi-function switch terminal 1,
- through 50 A fusible link (letter F , located in the fuse and fusible link box)
- to BCM terminal 55,
- through 10 A fuse [No. 21, located in the fuse block (J/B)]
- to BCM terminal 42.

With the ignition switch turned to ON or START position, Power is supplied
- through 15 A fuse [No. 1, located in the fuse block (J/B)]
- to BCM terminal 38.
- through 10 A fuse [No. 12, located in the fuse block (J/B)]
- to rear window defogger relay terminal 1.

With the ignition switch turned to ACC or ON position,
- through 10 A fuse [No. 6, located in the fuse block (J/B)]
- to multi-function switch terminal 2.

Ground is supplied
- to BCM terminal 52
- through body grounds M16 and M70,
- to multi-function switch terminal 14
- through body grounds M16 and M70,
- to IPDM E/R terminals 38 and 51
- through body grounds E22 and E43.

When rear window defogger switch in multi-function switch is turned to ON.
Then multi-function switch recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signals to AV control unit (without navigation system) or NAVI control unit (with navigation system) via AV line.
When AV control unit (without navigation system) or NAVI control unit (with navigation system) receives rear window defogger switch signals, and display on the screen.
Then AV control unit (without navigation system) or NAVI control unit (with navigation system) recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signal to BCM via DATA LINE (CAN H, CAN L). Then BCM recognizes that rear window defogger switch signal.

Then it sends rear window defogger request signal to IPDM E/R via DATA LINE (CAN H, CAN L).

When IPDM E/R receives rear window defogger switch signals, Ground is supplied l to rear window defogger relay terminal 2
- through IPDM E/R terminal 57
- through IPDM E/R terminal 51
- through body grounds E22 and E43. And then rear window defogger relay is energized. When rear window defogger relay is turned ON, signals are transmitted.
- through rear window defogger relay terminals 5 and 7
- through condenser terminal 1
- to rear window defogger terminal 1

Rear window defogger terminal 2 is grounded through grounds B702.
With power and ground supplied, rear window defogger filaments heat and defog the rear window.

When rear window defogger relay is turned to ON, Power is supplied
- through rear window defogger relay terminals 5 and 7
- through fuse block (J/B) terminal 2C
- through 10 A fuse [No. 8, located in the fuse block (J/B)] and
- through fuse block (J/B) terminal 5B
- to door mirror (LH and RH) terminal 4.
Door mirror (LH and RH) terminal 8 is grounded through body grounds M16 and M70.

With power and ground supplied, door mirror defogger filaments heat and defog the mirror.

CAN Communication System Description
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

CAN Communication Unit
Refer to LAN-34, "Information Bus". Description and Operation