Circuit/System Verification

WARNING: This page is about a different car, the 2016 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If the green LED is off with the ignition ON and the LED does not function when commanded with the scan tool, contact the OnStar® Center to confirm the vehicle has a current subscription.

Ignition ON/vehicle in Service Mode.
Verify no DTCs are set.
- If any DTCs are set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle
- If no DTCs are set
Verify that the Green Indicator turns ON and OFF when commanding the Green Indicator ON and OFF with a scan tool.
- If the Green Indicator does not turn ON and OFF
  Refer to Circuit/System Testing - Green Indicator Test
- If the Green Indicator turns ON and OFF
Verify that the Red Indicator turns ON and OFF when commanding the Red Indicator ON and OFF with a scan tool.
- If the Red Indicator does not turn ON and OFF
  Refer to Circuit/System Testing - Red Indicator Test
- If the Red Indicator turns ON and OFF
All OK.