LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2007 >> Allure CX >> Repair and Diagnosis >> External Pages >> Different car >> Section 65 (Engine Control System & Fuel System - 3.8L - DTC P0016 To DTC P0350) >> DTC P0128 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the ECT sensor.
  2. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PCM.
  3. Ignition ON, verify the scan tool ECT Sensor parameter is colder than -39°C (-38°F).
    • If warmer than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the PCM.
  4. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT Sensor parameter is warmer than 149°C (300°F).
    • If colder than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.
  5. If all circuits test normal, test or replace the ECT sensor.