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

Tests 1 - 3:

Tests 4 - 5:

SYMPTOM
BUS ± SIGNALS OPEN OR NO RESPONSE FROM THATCHAM ALARM MODULE

POSSIBLE CAUSES
- Attempt to communicate with the BCM
- Ground circuit open
- Fused ignition switch output circuit open
- Open PCI bus circuit
- Thatcham alarm module