Test D: The Defrost System Is Inoperative

PINPOINT TEST D: THE DEFROST SYSTEM IS INOPERATIVE

Normal Operation
When the rear defrost switch on the HVAC module is pressed, a ground signal is sent to the smart junction box (SJB) on circuit 1426 (PK). The SJB then grounds circuit 1389 (WH) which energizes the heated rear window relay. When the relay is active, voltage is supplied to the heated rear window grid through circuit 186 (BN/LB). The heated rear window grid is grounded by circuit 1205 (BK). The SJB provides heated backlite status to the HVAC module through circuit 1427 (TN/LB).







This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Heated rear window relay
- HVAC module
- Heated rear window grid
- SJB

D1-D3:

D3-D5:

D5-D6:

D6-D8:

D8-D9:

D10-D12:

D12-D14:

D14-D16:

D16-D18: