Test G: The Defrost System Does Not Shut Off Automatically - On At All Times

PINPOINT TEST G: THE DEFROST SYSTEM DOES NOT SHUT OFF AUTOMATICALLY - ON AT ALL TIMES

G1-G4:

G4-G5:

Normal Operation
Under normal operation, the heated backlight relay receives power from the central junction box (CJB) through circuit 185 (BK). When the rear window defrost switch is depressed on the temperature control module, a ground signal is sent to the instrument cluster module (ICM) through circuit 688 (GY/LB). When the ICM receives ground through circuit 688 (GY/LB), the ICM grounds circuit 1009 (OG/YE) to activate the heated backlight relay. Power is then sent to the rear window defrost grid through circuit 186 (BN/LB) from the heated backlight relay. The rear window defrost grid is grounded to the chassis through circuit 1205 (BK).

Possible Causes
- Inoperative ICM
- Inoperative heated backlight relay
- Short to voltage in circuit 186 (BN/LB)
- Short to ground in circuit 688 (GY/LB) or 1009 (OG/YE)
- Inoperative EATC or climate control module