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Home >> Chevrolet >> 2006 >> Impala LTZ >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.9L - DTC P0442 To DTC P2A01 >> DTC P1682 >> Circuit/System Testing
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Circuit/System Testing

  1. With the ignition OFF, remove and the ETC fuse from the underhood electrical center and inspect it.
    • If the fuse is open, test the Ignition 1 Voltage circuit from the ETC fuse to the ECM for a short to ground or for a faulty ECM.
  2. Remove the powertrain relay from the underhood electrical center. Connect a test lamp between the B+ terminal to the switch side of the relay and ground. The test lamp should illuminate.
    • If the test lamp does not illuminate, repair the open in the B+ feed circuit to the powertrain relay.
  3. Install the powertrain relay.
  4. With the ignition ON and the engine OFF, probe each side of fuse block terminals of the ETC fuse, with a test lamp connected to ground. The test lamp should illuminate on one side of the terminals.
    • If the test lamp does not illuminate. test the circuit from the powertrain relay to the ETC fuse for an open/high resistance, or for a faulty powertrain relay.
    • If the test lamp illuminates on both terminals, test the Ignition 1 Voltage circuit between the ETC fuse and the ECM for a short to voltage or for a faulty ECM.
  5. Connect a fused jumper wire to a B+ source.
  6. Observe the EC Ignition Relay Feedback Signal parameter on the scan tool. Probe the ECM side of the ETC fuse terminal with the jumper wire. The parameter should be more than 10 volts.
    • If the voltage is less than 10 volts, inspect the electrical center for corrosion or spread terminals, test the Ignition 1 Voltage circuit between the ETC fuse and the ECM for an open/high resistance, or for a faulty ECM. All circuit resistance should measure less than 3 ohms.
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