P0113
DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage
Circuit Description
The Intake Air Temperature (IAT) sensor is a thermistor that controls the signal voltage to the PCM. The PCM supplies a 5 V reference circuit and a ground circuit to the sensor. When the air is cold, the resistance will be high. When the intake air is warm, the resistance will be low.
Conditions for Running the DTC
- The engine run time is more than 320 seconds.
- The engine coolant temperature (ECT) is more than -40° C (-40° F).
- The vehicle speed sensor indicates that vehicle speed is less than 15 mph (24 kph).
Conditions for Setting the DTC
The IAT sensor signal voltage indicates that the intake air temperature is less than -40° C (-40° F) for 3 seconds.
Action Taken When the DTC Sets
- The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.
- The control module sets the DTC and records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tool's Freeze Frame and Failure Records.
Conditions for Clearing the MIL/DTC
- The control module turns OFF the MIL after 3 consecutive drive trips during which the diagnostic test Runs and Passes.
- A history DTC clears after 40 consecutive warm-up cycles during which no fault is detected. A warm up cycle occurs when the coolant temperature rises 22° C (40° F) above the startup temperature and exceeds 70° C (158° F) during the same ignition cycle.
- The DTCs can be cleared using the scan tool Clear Information function.
Diagnostic Aids
- When 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 to evaluate the possibility of an incorrectly calibrated sensor. Refer to Temperature vs Resistance.
Steps 1 - 4:
Steps 5 - 9:
Steps 10 - 13:
Test Description
The numbers below refers to the step numbers on the Diagnostic Table.
1. The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data 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 checks for the following conditions:
- An open ground circuit
- A short to voltage in the signal circuit
- A malfunctioning PCM
11. Program the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Isuzu Technical Communications System (ITCS) information