Diagnostic Instructions
Reference Information
Schematic Reference
OnStar Schematics
Connector End View Reference
Entertainment/Communication Connector End Views
Electrical Information Reference
Circuit/System Verification
Ignition ON, verify the OnStar® voice recognition is operating normally.
Circuit/System Testing
- Ignition OFF, disconnect the C3 harness connector at the CIM.
- Ignition ON, test for 8.5-9.5 volts between the navigation voice signal circuit terminal 2 and ground.
⇒ | If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
⇒ | If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
- Ignition OFF, test for less than 10 ohms between the navigation voice low reference circuit terminal 4 and ground.
⇒ | If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio. |
- Ignition ON, test for 8.5-9.5 volts between the navigation voice signal circuit terminal 2 and the drain wire circuit terminal 5.
⇒ | If less than specified range, test the drain wire circuit for a short to voltage or an open/high resistance. |
- Ignition OFF, disconnect the C1 harness connector at the radio.
- Verify that a test lamp does not illuminate between B+ and the navigation voice low reference circuit terminal 5.
⇒ | If the test lamp illuminates, test the low reference circuit for a short to ground. |
- If all circuits test normal, replace the CIM.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for radio replacement, setup, and programming