GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 STS 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Navigation System - Voice Recognition Inoperative

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

With OnStar®

  1. Verify the OnStar® voice recognition is operating normally.
    2. ⇒If the OnStar® voice recognition is inoperative, refer to .
  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.
    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.
    5. ⇒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.
    8. ⇒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.
    9. ⇒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.
    10. ⇒If greater than specified value, repair open circuit.
  10. If all circuits test normal, replace the radio.

Without OnStar®

  1. Ignition OFF, disconnect the harness connector at the rearview mirror.
  2. Ignition ON, test for greater than 9 volts between the terminal 2 and ground.
    3. ⇒If less than specified value, test the cellular microphone signal circuit for an ope/high resistance, for a short to ground, or for a short to the drain wire. If the circuit tests normal, test or replace the radio.
  3. Test for greater than 9 volts between the terminal 2 and the terminal 10.
    4. ⇒If less than specified value, test the drain wire for an open/high resistance. If the circuit tests normal, test or replace the radio.
  4. If all circuit test normal, replace the rearview mirror assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for radio replacement, setup, and programming
    •  Inside Rearview Mirror Replacement