Bus (+/-) Signals Open/No Response From ATC Module

Tests 1 - 4:

Tests 5 - 6:

SYMPTOM
BUS ± SIGNALS OPEN OR NO RESPONSE FROM AUTOMATIC TEMPERATURE CONTROL MODULE

POSSIBLE CAUSES
- Attempt to communicate with the BCM
- Ground circuit open
- Fused (B+) CKT open
- Fused ignition switch output circuit open
- Open PCI bus circuit
- Automatic temperature control module