Perform the Diagnostic System Check - Vehicle .

The infotainment unit is fully illuminated. The infotainment unit receives the illumination control signal from the hardwired illumination input on the connector. The actual dimming value is received from the BCM via GMLAN. The infotainment unit illumination test is performed using a scan tool, and controls the fascia illumination directly to verify correct operation.

Scan Tool Reference

Control Module References

Important: It is recommended that component testing is performed before circuit testing when diagnosing infotainment unit functions.

1. Turn the park lamps on.
2. Connect the scan tool to the DLC and select Infotainment System / Audio System / Actuator Test / Display / Illumination .
3. Ignition On, infotainment unit On.
4. Using the Increase soft key on the scan tool, increase the illumination level to maximum.
5. Check the display illumination is even with no dark patches, and the fascia control buttons are illuminated.
6. To decrease the infotainment unit illumination, press the Decrease soft key on the scan tool. Check the fascia illumination decreases accordingly.
7. Press the Quit soft key to exit the test.

⇒	If the illumination function does not operate correctly, replace the infotainment unit.

Perform the Diagnostic Repair Verification .

Radio Replacement