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Home >> Saturn >> 2006 >> Ion Red Line >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Engine Controls - 2.4L - DTC P0010 To DTC P0341) >> DTC P0125 or P0128 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2006 Saturn Ion 3. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn OFF the ignition, and all electrical accessories. Allow sufficient time for all of the control modules to power down before taking a resistance measurement.
  2. Disconnect the ECT sensor.
  3. Measure for a proper value of less than 5 ohms of resistance between the ECT low reference circuit and a good ground.
    • If the resistance is more than 5 ohms, test the low reference circuit for a high resistance.
    • If the ECT low reference circuit tests normal, then replace the ECM.
  4. Disconnect the ECM.
  5. Measure for a proper value of less than 5 ohms of resistance on the ECT sensor signal circuit.
    • If the resistance is more than 5 ohms, repair the high resistance in the ECT sensor signal circuit.
  6. Remove and test the ECT sensor. Observer the component testing procedure below.
    • If the resistance measurements of the ECT sensor are out of range, replace the sensor.
    • If the ECT sensor tests normal and the DTC continues to set, then replace the ECM.
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