Code P0113, IAT Sensor Circuit (High Temperature Indicated): Notes

1994 Chevrolet Lumina BaseSECTION Notes

The Intake Air Temperature (IAT) sensor is a thermistor. PCM applies and monitors 5 volts on circuit to sensor. When air is cold, sensor resistance is high and PCM will measure a high signal voltage. If air is warm, sensor resistance is low causing PCM to measure low voltage.

Code P0113 will set when following conditions are present.

  • Signal voltage indicates an intake air temperature greater than 284°F (140°C).
  • Vehicle speed is greater than 35 MPH.
  • Above conditions are met for at least for 5 seconds.

With Code P0113 set, PCM will use a default value of 61°F (16°C) for intake air temperature. Code P0113 does not illuminate Malfunction Indicator Light (MIL).

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. Tech-1 may be used to diagnose this fault since PCM transmits actual values when fault is present. A grounded circuit will cause Tech-1 to display a temperature of approximately 297°F (147°C).
  2. If Tech-1 displays -40° with IAT sensor disconnected, PCM and wiring are okay. Replace IAT sensor.
RENDER: 1.0x

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