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Home >> Hummer >> 2008 >> H3 Base, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 168 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Navigation System - Voice Recognition Inoperative >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

North American

  1. Ignition OFF, disconnect the X3 harness connector at the VCIM.
  2. 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.
  3. 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.
  4. 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. If the circuit tests normal, replace the radio.
  5. Ignition OFF, disconnect the X1 harness connector at the radio.
  6. 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.
  7. If all circuits test normal, replace the VCIM.

European

  1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
  2. Ignition ON, test for 8.5-9.5 volts between the cellular microphone signal circuit terminal 10 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.
  3. Ignition ON, test for 8.5-9.5 volts between the cellular microphone signal circuit terminal 10 and the drain wire circuit terminal 2.
    • If less than specified range, test the drain wire circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio.
  4. If all circuits test normal, replace the inside rearview mirror assembly.
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