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Home >> Chevrolet >> 2006 >> Chevy Express G2500, Van Cargo Extended, 6.6 2 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 6.6L (LLY) - DTC P0016 To DTC P0342 >> DTC P0116 >> Circuit/System Verification

Circuit/System Verification

  1. If the ignition has been OFF for 10 hours or more, the ECT and the IAT should be within 6°C (11°F) of each other, and also the ambient temperature. Turn ON the ignition, with the engine OFF, and use a scan tool to observe the IAT and the ECT sensor parameters. Compare those sensor parameters to each other, and also to the ambient temperature. A slight to moderate resistance in the IAT signal or low reference circuit can widen the spread between the two sensors and cause this DTC to set.
  2. An IAT sensor that is skewed lower at various ambient temperatures, due to more resistance than is normal, can widen the spread between the two sensors and cause this DTC to set. Measure and record the resistance of the IAT sensor at various ambient temperatures, then compare those measurements to the Temperature vs. Resistance table. Refer to Temperature vs Resistance (ECT Sensor) or Temperature vs Resistance (IAT Sensor) or Temperature vs Resistance (IAT 2 Sensor) or Temperature vs Resistance (Fuel Temperature) .
  3. Use the scan tool Ignition OFF parameter and a watch to determine if the internal clock of the ECM is working properly.
  4. Inspect the ECT sensor terminals for corrosion and for engine coolant leaking through the sensor.
    5. CAUTION: Under pressure, the temperature of the solution in the radiator can be considerably higher, without boiling. Removing the radiator cap while the engine is hot (pressure is high), will cause the solution to boil instantaneously, with explosive force. The solution will spew out over the engine, fenders, and the person removing the cap. Serious bodily injury may result. Flammable antifreeze, such as alcohol, is not recommended for use at any time. Flammable antifreeze could cause a serious fire.
  5. Turn OFF the ignition.
  6. Inspect the cooling system surge tank for the proper engine coolant level. Refer to Cooling System Leak Testing and Draining and Filling Cooling System (Static Fill) or Draining and Filling Cooling System (Vac N Fill) .
IMPORTANT: The engine needs to have been OFF for at least 10 hours for the ECT and the IAT to be at ambient temperature. The vehicle should not have changed environments during this time.
IMPORTANT: The IAT sensor will start to warm-up as soon as the ignition is turned ON.
  1. Set up the scan tool to take a snapshot of engine data.
  2. Turn on the ignition.
  3. Take snapshot with the scan tool.
  4. The difference between the ECT parameter and the IAT parameter should be less than 6°C (11°F).
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