Test E: The Defrost System Is Inoperative

PINPOINT TEST E: THE DEFROST SYSTEM IS INOPERATIVE

E1-E2:

E2-E3:

E3 Continued:

E4-E5:

E6-E7:

E7-E8:

Normal Operation
The heated rear window is controlled by the electronic automatic temperature control (EATC). The ignition switch must be in RUN for the EATC to operate. When the rear window defrost button is pressed, the EATC provides a ground for the heated rear window relay coil through circuit 688 (GY/LB). The heated rear window relay coil is energized, providing battery voltage to the antenna module on circuit 186 (BN/LB). The antenna module then supplies voltage and ground to the heated rear window grid.

Possible Causes
- Fuse(s)
- Circuit 185 (BK) open
- Circuit 186 (BN/LB) open or short to ground
- Circuit 640 (RD/YE) open
- Circuit 688 (GY/LB) open or short to voltage
- Heated rear window relay
- Antenna module
- Heated rear window grid
- EATC