LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2006 >> G6 GTP, 2D Convertible >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.9L - DTC P0010 To DTC P0300 >> DTC P0116 or P0128 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

P0116 Only

    The vehicle should be OFF for at least 8 hours for the ECT and the IAT to be at ambient temperature. The vehicle should not have changed environments during this time.

    IMPORTANT: The cooling fans are commanded ON when certain ECT DTCs are set.
  1. Inspect for the following conditions:

    • Inspect the cooling system coolant level, if low then refer to Loss of Coolant .
    • Corrosion on the ECT terminals
    • Improper or corroded terminals at the ECT harness connector
    • Loose terminals in the ECT harness connector
    • Inspect for the ECT sensor for leaking engine coolant internally through the sensor

  2. With the key ON, engine OFF, measure for 4.8-5.2 volts from the signal circuit of the ECT sensor to a good ground with a DMM.
    • If not within 4.8-5.2 volts, test the ECT sensor signal circuit for high resistance, or for an intermittent and for a poor connection at the control module. If circuits test normal, replace the control module.
  3. Measure for 4.8-5.2 volts from the signal circuit of the ECT sensor to the low reference circuit of the ECT sensor with a DMM.
    • If not within 4.8-5.2 volts, test the ECT sensor low reference circuit for high resistance, or for an intermittent and for a poor connection at the control module.
    • If circuits test normal, replace the control module.
  4. Measure for 4.8-5.2 volts from the IAT signal circuit to a good ground with a DMM.
    • If not within 4.8-5.2 volts, test the IAT signal circuit for a high resistance, or for an intermittent and for a poor connection at the control module. If circuits test normal, replace the control module.
  5. Measure for less than 5 ohms of resistance from the low reference circuit of the IAT sensor to a good ground with a DMM.
    • If more then 5 ohms, test the IAT low reference circuit for high resistance or for an intermittent and for a poor connection at the control module. If circuits test normal, replace the control module.
  6. Observe and record the ambient air temperature of the vehicle environment using an accurate thermometer.
  7. After the vehicle has been OFF for 8 hours, remove the mass air flow (MAF)/IAT sensor, and ECT sensor.
  8. Place the sensors on a work surface away from any heat source. Allow the sensors to reach the ambient air temperature for 30-60 minutes.
    9. IMPORTANT: The IAT sensor will start to warm-up as soon as the ignition is turned ON.
  9. Connect the MAF/IAT sensor and the ECT sensor to the electrical connector, but DO NOT install them. Insulate the sensors from any engine heat source.
  10. Turn ON the ignition and take a snapshot of the Engine Data List with a scan tool. Refer to Scan Tool Snapshot Procedure.
  11. Observe the recorded IAT Sensor parameters from the scan tool. Compare the differences between the IAT Sensor parameter, and the ambient air temperature more than 8°C (14°F).
    • If more than 8°C (14°F), replace the IAT sensor.
  12. Review the snapshot data that was taken with the scan tool. Observe the ECT Sensor and IAT Sensor parameters with a scan tool for a difference of less than 15°C (27°F).
    • If more than 15°C (27°F), replace the ECT sensor.
scientia non olet · About LEMON Manuals