Bus (+/-) Signals Open From ATC Module

Test 1 - 2:

Test 3 - 6:

Test 7 - 8:

SYMPTOM
BUS +/- SIGNALS OPEN FROM ATC

TEST NOTE
This symptom is diagnosed using the test ATC MESSAGES NOT RECEIVED.

POSSIBLE CAUSES
- Ground wire open
- PCI bus circuit open
- Fused ignition switch output circuit short to ground
- Fused ignition switch output CKT open
- Fused ignition switch output wire short to ground
- ATC head
- ATC head