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Home >> Lexus >> 2012 >> IS 250 AWD V6-2.5L (4GR-FSE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0113

P0113





4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0112, P0113: Intake Air Temperature Circuit Low Input
P0113 - Intake Air Temperature Circuit High Input

DESCRIPTION





- The Intake Air Temperature (IAT) sensor, mounted on the Mass Air Flow (MAF) meter, monitors the IAT. The IAT sensor has a built in thermistor with a resistance that varies according to the temperature of the intake air. When the IAT is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes (See Fig. 1).

- The IAT sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R.

- Resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor changes, according to changes in the IAT, the voltage at terminal THA also varies. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.

HINT
When any of DTCs P0112 and P0113 are set, the ECM enters fail-safe mode. During fail-safe mode, the IAT is estimated to be 20°C (68°F) by the ECM. Fail-safe mode continues until a pass condition is detected.





HINT
When any of these DTCs are set, check the IAT by entering the following menus on Techstream: Powertrain / Engine / Data List / All Data / Intake Air.





MONITOR DESCRIPTION

The ECM monitors the sensor voltage and uses this value to calculate the Intake Air Temperature (IAT). When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a malfunction in the IAT sensor and sets a DTC.

- Example:

- If the sensor output voltage is more than 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 less 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

1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on.

6. Wait 0.5 seconds or more.

7. Enter the following menus: Powertrain / Engine / Trouble Codes.

8. Read the pending DTC.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

10. Input the DTC: P0112 or P0113.

11. Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.

12. If the test result is INCOMPLETE or N/A 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





INSPECTION PROCEDURE

HINT
- If other DTCs relating to different systems that have terminal E3 as the ground terminal are output simultaneously, terminal E3 may have an open circuit.
- Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction Freeze Frame Data.

PROCEDURE

1. READ VALUE USING TECHSTREAM (INTAKE AIR)

(a) Connect Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

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

(e) Read the value displayed on the Techstream.

Standard:

Same as actual Intake Air Temperature (IAT).

Result:





HINT
- If there is an open circuit, Techstream indicates -40°C (-40°F).
- If there is a short circuit, Techstream indicates higher than 128°C (262°F).

B -- CHECK MASS AIR FLOW METER (CHECK FOR SHORT IN SENSOR)

C -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
A -- Continue to next step.

2. CHECK MASS AIR FLOW METER (CHECK FOR OPEN IN SENSOR)

(a) Confirm good connection of the mass air flow meter.





(b) Disconnect the E29 Mass Air Flow (MAF) meter connector.

(c) Connect terminals THA and E3 of the MAF meter wire harness side connector.

(d) Connect Techstream to the DLC3.

(e) Turn the engine switch on (IG).

(f) Turn the Techstream on.

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

(h) Read the value displayed on the Techstream.

Standard:

Higher than 128°C (262°F)

(i) Reconnect the MAF meter connector.

OK -- REPLACE MASS AIR FLOW METER Removal
NG -- Continue to next step.

3. CHECK ECM (CHECK FOR OPEN IN ECM)

(a) Confirm good connection of the ECM.





(b) Disconnect the E29 MAF meter connector.

(c) Connect terminals THA and E3 of the E5 ECM connector.

HINT
Before checking, do visual and contact pressure checks on the ECM connector.

(d) Connect Techstream to the DLC3.

(e) Turn the engine switch on (IG).

(f) Turn the Techstream on.

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

(h) Read the value displayed on the Techstream.

Standard:

Higher than 128°C (262°F)

(i) Reconnect the MAF meter connector.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

NG -- REPLACE ECM Removal

4. CHECK MASS AIR FLOW METER (CHECK FOR SHORT IN SENSOR)

(a) Disconnect the E29 MAF meter connector.





(b) Connect Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

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

(f) Read the value displayed on the Techstream.

Standard:

-40°C (-40°F)

(g) Reconnect the MAF meter connector.

OK -- REPLACE MASS AIR FLOW METER Removal
NG -- Continue to next step.

5. CHECK ECM (CHECK FOR SHORT IN ECM)

(a) Disconnect the E5 ECM connector.





(b) Connect Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

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

(f) Read the value displayed on the Techstream.

Standard:

-40°C (-40°F)

(g) Reconnect the ECM connector.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR

NG -- REPLACE ECM Removal
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