Circuit/System Testing

With OnStar®

1. Verify the OnStar® voice recognition is operating normally.
   • If the OnStar® voice recognition is inoperative, refer to Voice Recognition Inoperative .
2. Ignition OFF, disconnect the radio harness connector C3 and VCIM harness connector X3.
3. Test for less than 1 volt on the C3 radio harness connector terminal 4.
   • If greater than specified value, repair short to voltage.
4. Test for greater than 1 ohm between the C3 radio harness connector terminal 4 and ground.
   • If less than specified value, repair short to ground.
5. Test for less than 1 ohm between the C3 radio harness connector terminal 4 and the C3 VCIM harness connector terminal 2.
6. If greater than specified value, repair open circuit.
7. Test for less than 1 volt on the C3 radio harness connector terminal 5.
   • If greater than specified value, repair short to voltage.
8. Test for greater than 1 ohm between the C3 radio harness connector terminal 5 and ground.
   • If less than specified value, repair short to ground.
9. Test for less than 1 ohm between the C3 radio harness connector terminal 5 and C3 VCIM harness connector terminal 4.
   • If greater than specified value, repair open circuit.
10. If all circuits test normal, replace the radio.