Test F: The Defrost System is Inoperative
PINPOINT TEST F: THE DEFROST SYSTEM IS INOPERATIVEF1-F3:
F3-F6:
F6-F9:
F9-F11:
F11-F13:
F13-F15:
F16-F18:
Normal Operation
The BEC rear window defrost relay receives 12 volts from the BEC fuse 13 (40A). Once the rear window defrost relay is energized by the smart junction box (SJB), 12 volts are supplied to the rear window defrost grid on circuit 186 (BN/LB). The rear window defrost switch supplies a request signal on circuit 1426 (PK) to the SJB. The rear window defrost switch indicator illuminates on circuit 1427 (TN/LB). When the request is received, the SJB energizes the rear window defrost relay by supplying 12 volts on circuit 298 (VT/OG) and controlling the ground on circuit 1389 (WH).
Possible Causes
- Circuit 1389 (WH) open or short to voltage
- Circuit 186 (BN/LB) open
- Circuit 1205 (BK) open
- Circuit 1426 (PK) open or short to ground
- Circuit 1427 (TN/LB) short to battery or short to ground
- Circuit 298 (VT/OG) open
- Rear window defrost relay
- BEC
- SJB
- Rear window defrost grid
- Fuse