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Home >> Hummer >> 2010 >> H3 Alpha >> Repair and Diagnosis >> External Pages >> Different car >> Section 1428 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> OnStar Button Malfunction >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the OnStar® button assembly.
  2. Test for less than 10 Ω between the button assembly ground circuit terminal E and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, test for less than 1 V between the keypad signal circuit terminal B and ground.
    • If greater than the specified range, test the keypad signal circuit for a short to voltage. If the circuit tests normal, replace the CIM.
  4. Ignition OFF, test for 600 k-800 k Ω between the keypad signal circuit terminal B and ground.
    • If less than the specified range, test the keypad signal circuit for a short to ground. If the circuit tests normal, replace the CIM.
    • If greater than the specified range, test the keypad signal circuit for an open/high resistance. If the circuit tests normal, replace the CIM.
  5. Ignition ON, test for 9.5-10.5 V between the keypad supply voltage circuit terminal A and ground.
    • If less than the specified range, test the supply voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the CIM.
    • If greater than the specified range, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the CIM.
  6. If all circuits test normal, test or replace the button assembly.
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