P0113

Refer to Engine Controls Schematics PCM A/C Pressure, TPS MAP ECT IAT

Diagnostic Chart:

CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor which measures the temperature of the air entering the engine. The PCM applies 5.0 V through a pull up resistor. When the intake air is cold, the sensor resistance is high and the PCM will monitor a high signal voltage on the IAT sensor signal circuit. As the intake air warm, the sensor resistance becomes lower causing the PCM to monitor a lower voltage. If the PCM detects an excessively high IAT sensor signal voltage (low temperature indicated), DTC P0113 will set.

CONDITIONS FOR RUNNING THE DTC
^ Active ECT, MAF sensor or VSS DTC are not present.
^ Vehicle speed is less than 56 km/h (35 mph).
^ MAF is less than 12 gm/s.
^ ECT is more than 60°C (140°F).
^ The Engine run time is more than 3 minutes.

CONDITIONS FOR SETTING THE DTC
^ IAT signal voltage indicates an intake air temperature less than 37°C (-35°F).
^ The above conditions are present for at least 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
^ If the misfire is determined to be catalyst damaging, the PCM will flash the MIL.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
Inspect for the following conditions:
^ Poor connection at the PCM may be caused by the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal to wire connection
^ Damaged harness
^ Intermittents-If the harness appears to be OK, observe the IAT display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the malfunction. Refer to Testing for Intermittent and Poor Connections or to Wiring Repairs in Diagrams.

If DTC P0113 cannot be duplicated, the information included in the Fail Records data can be useful in determining vehicle mileage since the DTC was last set.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
2. Verifies that the fault is present.
3. If DTC P0113 can be repeated only by duplicating the Fail Records conditions. The Temperature vs Resistance table may be used to test the IAT sensor at various temperatures to evaluate the possibility of a shifted sensor that may be open above or below a certain temperature. If this is the case, replace the IAT sensor. If the IAT sensor appears to be OK, the fault is intermittent. Refer to Diagnostic Aids.
5. Use a fused jumper during this test. If the IAT signal circuit is shorted to battery or ignition positive voltage the fuse in the jumper will open, indicating a short in the signal circuit.
12. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.