Test K: the Defrost System Is Inoperative
PINPOINT TEST K: THE DEFROST SYSTEM IS INOPERATIVEK1-K3:
K3 Continued:
K4-K5:
K5-K6:
Normal Operation
During normal operation, the electronic automatic temperature control (EATC) module or electronic manual temperature control (EMTC) activates the rear window defrost relay by grounding the relay coil through circuit CH122 (WH/OG). When the defrost relay is activated, power is supplied from the relay to the rear window defrost grid through circuit CRD06 (BN/YE) and also to the LH/RH exterior rear view mirror heaters through circuit CBB23 (BN/YE). Ground is supplied to the rear window defrost grid and exterior mirror heaters through circuit GD150 (BK/WH).
Possible Causes
- Fuse(s)
- Rear window defrost relay
- Open in circuit CH122 (WH/OG), CRD06 (BN/YE) or GD150 (BK/WH)
- EATC module
- EMTC module
- Open or short in rear window defrost grid