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Home >> Cadillac >> 2012 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 785 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P1668 >> Circuit/System Testing
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Circuit/System Testing

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  1. With ignition ON, and the engine OFF, disconnect the generator harness and measure the voltage of the generator turn ON signal circuit, should read near 0 volts.
    • If greater than 0 volts, test the generator turn ON signal circuit for a short to voltage or replace the ECM.
  2. With ignition ON, and the engine running, the voltage of the generator turn ON signal circuit, should read over 3.5 volts.
    • If no voltage is measured, test the generator turn ON signal circuit for a short to ground, an open or a high resistance or replace the ECM.
  3. Refer to Charging System Test .
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