Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The radio generates the audible warning through the left speaker. The radio receives audible warning requests via GMLAN serial data from the instrument panel cluster (IPC) or the body control module (BCM).

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

Important: Before performing this diagnostics, make sure no indicator(s) are illuminated after the IPC performs a lamp test. If any indicators are illuminated after the bulb test, perform the indicator diagnostics before this diagnostics.

1. Ignition ON, headlamp switch OFF, verify the scan tool Headlamp Switch parameter is Inactive.

⇒	If not Inactive, refer to Headlamps Malfunction .

2. Ignition ON, park lamp switch OFF, verify the scan tool Park Lamps Switch parameter is Inactive.

⇒	If not Inactive refer to Park, License, and/or Tail Lamps Malfunction

3. Ignition ON, doors closed, verify the scan tool All Door Lock Command is On.

⇒	If not On, refer to Courtesy Lamps Malfunction .

4. Ignition OFF, key out of the ignition, verify the scan tool Key In Ignition Status parameter is Inactive.

⇒	If not Inactive, test the key in ignition switch signal circuit for a short to ground. If the circuits tests normal, replace the ignition switch.

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Ignition and Start Switch Replacement