Circuit/System Verification

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT:

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

Ignition ON, headlamp switch OFF, verify the scan tool Headlamp Switch ON parameter is Inactive.
- If not Inactive, refer to Headlamps Malfunction (With X88, Z75, and Z88) , Headlamps Malfunction (With T4Q) .
Ignition ON, park lamp switch OFF, verify the scan tool Park Lamp Switch parameter is Inactive.
- If not Inactive, refer to Park, License, and/or Tail Lamps Malfunction (Front LED Park/Marker Lamps with T4Q) , Park, License, and/or Tail Lamps Malfunction (With X88, Z75, and Z88) .
Ignition ON, doors closed, verify the scan tool Door Ajar Switch parameters are Inactive.
- If not Inactive, refer to Courtesy Lamps Malfunction .
Ignition ON, radio ON, adjust the radio balance and fade to the left front speaker.
- If the speaker does not operate properly, refer to Speaker Malfunction .
Verify that the Key In Ignition Status parameter is Key In when the key is in the ignition and Key Out when the key is out of the ignition.