FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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P0113

DTC P0113 INTAKE AIR TEMPERATURE CIRCUIT HIGH INPUT

CIRCUIT DESCRIPTION




DTC Detection Condition:




The intake air temperature (IAT) sensor, mounted on the mass air flow (MAF) meter, monitors the intake air temperature. The IAT sensor has a thermistor that varies its resistance depending on the temperature of the intake air. When the air temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected as voltage changes to the ECM terminal (see Fig. 1).

The intake air temperature sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the intake air temperature sensor from terminal THA (THAR) via resistor R.

That is, the resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the voltage at terminal THA (THAR) also changes. Based on this signal, the ECM increases the fuel injection volume to improve the driveability during cold engine operation.






HINT: After confirming DTC P0110, P0112 or P0113, use the hand-held tester or the OBD II scan tool to confirm the intake air temperature in the DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL.

MONITOR DESCRIPTION

Monitor Strategy:




Typical Enabling Conditions:




Typical Malfunction Thresholds:




Component Operating Range:




The ECM monitors the sensor voltage and uses this value to calculate the intake air temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the IAT sensor and sets a DTC.

Example: When the sensor voltage output equal to -40 °C (-40 °F), or more than 140 °C (284 °F).

Wiring Diagram:






Step 1:




Step 2 - 3:




Step 3 (Contd.) - 5:




INSPECTION PROCEDURE

HINT:
- If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

CHECK FOR INTERMITTENT PROBLEMS

HINT:
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with a hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default) using 2 trip detection logic.
a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.