Bus (+/-) Signals Open/No Response From Instrument Cluster

Tests 1 - 4:

Tests 5 - 6:

SYMPTOM
BUS ± SIGNALS OPEN OR NO RESPONSE FROM INSTRUMENT CLUSTER

POSSIBLE CAUSES
- Attempt to communicate with the CTM
- Open ground circuit(s)
- Open fused ignition switch output circuits
- Open fused B+ circuit
- Open PCI bus circuit
- Instrument cluster