No Response From Controller Antilock Brake

Test 1 - 3:

Test 4 - 8:

Test 9 - 10:

SYMPTOM
NO RESPONSE FROM CAB

POSSIBLE CAUSES
- PCI Bus open to CAB
- Fused ignition switch output circuit intermittently shorted to ground
- Fused ignition switch output circuit open
- Fused ignition switch output circuit shorted to ground
- Ground circuit open
- CAB defective - fused ignition switch output shorted to ground
- CAB defective - can not communicate