Test D: The Defrost System Is Inoperative
PINPOINT TEST D: THE DEFROST SYSTEM IS INOPERATIVED1-D2:
D2-D3:
D3-D5:
D5-D6:
D6-D8:
D8-D9:
D10-D12:
D12-D14:
D14-D16:
D16-D18:
Normal Operation
When the rear defrost switch on the climate control assembly is pressed, a ground signal is sent to the smart junction box (SJB) on circuit 1426 (PK). The SJB then grounds circuit 1389 (WH). This energizes the heated rear window relay, allowing voltage to be supplied to the heated rear window grid through circuit 186 (BN/LB). The heated rear window grid is grounded by circuit 1205 (BK).
Possible Causes
- Fuse(s)
- Circuit 186 (BN/LB) open
- Circuit 298 (VT/OG) open
- Circuit 1205 (BK) open
- Circuit 1389 (WH) open or short to voltage
- Circuit 1426 (PK) open or short to ground
- Circuit 1427 (TN/LB) open, short to ground or short to voltage
- Heated rear window relay
- Heated rear window switch
- Heated rear window grid
- SJB