No PCI Messages From CD Changer

Test 1:

Tests 2 - 5:

SYMPTOM
NO PCI MESSAGES FROM CD CHANGER

WHEN MONITORED
With the ignition ON and the radio ON.

POSSIBLE CAUSES
- CD changer (DIN) cable
- CD changer PCI bus circuit open
- Ignition switch output circuit open
- Radio ground CKT open
- CD changer