Note. For circuit reference (Схема №3)
Circuit Description
Intake Air Temperature (IAT) sensor is a thermistor. PCM applies and reads a 5-volt reference signal 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.
Conditions required to set DTC are
- No ECT, MAF, or VSS sensor DTCs set.
- Engine running longer than 2 minutes.
- Vehicle speed is greater than 30 MPH.
- IAT signal voltage intermittently indicates IAT greater than 298°F (148°C), about .10 volt, for 2.5 seconds over a 25- second period.
Diagnostic Aids
Check for faulty connections or damaged harness. Observe IAT display on scan tool while moving all related harnesses and connectors. A change in scan tool display indicates fault location. Check for skewed IAT sensor. See IAT SENSOR RESISTANCE under DTC P0112. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.