P0113

3UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0110,P0112,P0113: Intake Air Temperature Circuit
P0113 - Intake Air Temperature Circuit High Input

DESCRIPTION





- The Intake Air Temperature (IAT) sensor, built into the Mass Air Flow (MAF) meter, monitors the intake air temperature. The IAT sensor has a thermistor that varies its resistance depending on the intake air temperature. When the intake 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 IAT sensor is connected to the ECM. The 5 V power source voltage in the ECM is applied to the IAT sensor from terminal THA via resistor R.

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





HINT
After confirming DTC P0110, P0112 or P0113, use the Techstream to confirm the intake air temperature by entering the following menus: Powertrain / Engine / Data List / Intake Air.





MONITOR DESCRIPTION

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:

If the sensor output voltage is 4.91 V for 0.5 seconds or more, the ECM determines that there is an open in the IAT sensor circuit, and sets DTC P0113. Conversely, if the output voltage is more than 0.18 V for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and sets DTC P0112. If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0112:





P0113:





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





- Connect the Techstream to the DLC3.

- Turn the ignition switch to ON and turn the Techstream on.

- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

- Turn the ignition switch off and wait for at least 30 seconds.

- Turn the ignition switch to ON and turn the Techstream on.

- Wait 0.5 seconds or more [A].

- Enter the following menus: Powertrain / Engine / Trouble Codes [B].

- Read the DTCs.

HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.

- Input the DTC: P0112 or P0113.

- Check the DTC judgment result.





- If the test result is INCOMPLETE or UNKNOWN and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM





INSEPCTION PROCEDURE

HINT
Read freeze frame data using the Techstream. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine / Data List / Intake Air.

(d) Read the values.

OK:

Same value as the actual IAT

Result:





HINT
If there is an open circuit, the Techstream indicates -40°C (-40°F).

If there is a short circuit, the Techstream indicates 140°C (284°F) or more.

C -- CHECK FOR INTERMITTENT PROBLEMS

B -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)





(a) Disconnect the M1 MAF meter connector.

(b) Connect terminal THA and E2 of the MAF meter's wire harness side connector.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON and turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Data List / Intake Air.

(f) Read the value.

Standard:

Temperature value is 140°C (284°F) or more

NG -- READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)

OK -- REPLACE MASS AIR FLOW METER Service and Repair

3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)





(a) Disconnect the M1 MAF meter connector.

(b) Connect terminal THA of the E4 ECM connector and terminal E2 of the E2 ECM connector.

HINT
Before checking, perform a visual and contact pressure check for the ECM connector.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON and turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Data List / Intake Air.

(f) Read the value.

Standard:

Temperature value is 140°C (284°F) or more

NG -- REPLACE ECM Service and Repair

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

4. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)





(a) Disconnect the M1 MAF meter connector.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON and turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Intake Air.

(e) Read the value.

Standard:

Temperature value is -40°C (-40°F)

NG -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN HARNESS OR ECM)

OK -- REPLACE MASS AIR FLOW METER Service and Repair

5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN HARNESS OR ECM)





(a) Disconnect the M1 MAF meter connector.

(b) Disconnect the E2 and E4 ECM connectors.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON and turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Data List / Intake Air.

(f) Read the value.

Standard:

Temperature value is -40°C (-40°F)

NG -- REPLACE ECM Service and Repair

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - INTAKE AIR TEMPERATURE SENSOR)