P0113

DTC P0113:

CIRCUIT DESCRIPTION
The Intake Air Temperature (IAT) sensor is a thermistor. The Powertrain Control Module (PCM) applies a voltage (about 5 volts) on CKT 472 to the sensor. When air is cold, the sensor resistance is high and the PCM will measure a high signal voltage. If the air is warm, the sensor resistance is low causing the PCM to measure a low voltage.

DIAGNOSTIC TROUBLE CODE (DTC) P0113 WILL SET WHEN
^ Signal voltage indicates an intake air temperature greater than 14O°C (284°F).
^ Vehicle speed is greater than 35 mph.
^ Both of the above requirements are met for at least 5 seconds.

ACTION TAKEN (PCM WILL DEFAULT TO)
With a current DTC P0113 set, the PCM will use a default value of 16°C (61°F) for intake air temperature. DTC P0113 does not illuminate the MIL (Service Engine Soon).

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. A Tech 1 may be used to diagnose this fault since the PCM transmits "actual" values when the fault is present. A grounded circuit will cause the Tech 1 to display a temperature of approximately 147°C (297°F).
2. If the Tech 1 displays -40°C with the IAT sensor disconnected, the PCM and wiring are OK and the IAT sensor must be replaced.

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation.

Check For:

Poor Connection or Damaged Harness
Inspect PCM harness for short to ground in CKT 472, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.

Intermittent Test
Observe Intake Air Temperature (IAT) on Tech 1 while moving related connectors and wiring harness with warm engine running. If the failure is induced, the IAT display will change to a 147°C (297°F) temperature reading. This may help to isolate the location of the malfunction.