P0113

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Intake Air Temperature (IAT) sensor uses a thermistor to control the signal voltage to the PCM. The PCM supplies a 5 V reference and a ground to the sensor. When the air is cold the resistance is high, therefore the IAT signal voltage will be high. If the intake air is warm, resistance is low, therefore the IAT signal voltage will be low.

Conditions for Setting the DTC

^ Engine run time is greater than 320 seconds.

^ Vehicle speed is less than 15 mph (24 km/h).

^ IAT is less than -40°C (-40°F).

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) will illuminate.

^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.

^ A history DTC is stored.

^ Coolant fan turns ON.

^ The PCM will default to 60°C (140°F) for intake air temperature. The scan tool wilt not the show the defaulted value.

Conditions for Clearing the MIL/DTC

^ The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.

^ A history DTC will clear after 40 consecutive warm up cycles without a fault.

^ DTC(s) can be cleared by using the scan tool.

Diagnostic Aids

^ If the vehicle is at ambient temperature compare the IAT sensor to the ECT sensor. The IAT sensor and the ECT sensor should be relatively close to each other.

^ Use the Temperature vs. Resistance Values table, refer to Temperature vs Resistance to evaluate the possibility of a skewed sensor. Specifications


Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored in the scan tool for later reference.

4. This step simulates a DTC P0112. If the PCM senses the change, the PCM and wiring are OK.

5. This step will determine if the reason the PCM did not sense the change was due to a open ground or signal circuit or malfunctioning PCM.

11. The replacement PCM must be programmed and the crankshaft position system variation procedure must be preformed. Refer to the latest Techline procedure for PCM reprogramming and also refer to Powertrain Control Module the Crankshaft Position System Variation Procedure.