SFI SYSTEM, Diagnostic DTC:P0112, P0113

DESCRIPTION

• The intake air temperature sensor, mounted on the mass air flow meter, monitors the intake air temperature. The intake air temperature sensor has a built-in thermistor with a resistance that varies according to the temperature of the intake air. When the intake air temperature 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.

• The intake air temperature sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor.

• Resistor and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes, according to changes in the intake air temperature, 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.

  Tech Tips

  When DTC P0112 or P0113 is stored, the ECM enters fail-safe mode. During fail-safe mode, the intake air temperature is estimated to be 20°C (68°F) by the ECM. Fail-safe mode continues until a pass condition is detected.

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 malfunction in the intake air temperature sensor circuit and stores a DTC.

CONFIRMATION DRIVING PATTERN

1. 

2. Connect the GTS to the DLC3.

3. Turn the ignition switch to ON and turn the GTS on.

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

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

6. Turn the ignition switch to ON and turn the GTS on.

7. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

8. With the vehicle stationary, depress the accelerator pedal and maintain an engine speed of between 2500 and 3000 rpm for 40 seconds or more [A].

9. Drive the vehicle at 10 km/h (6.25 mph) or more for 1 minute or more [B].

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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

11. Read pending DTCs.

    Tech Tips

    
    

    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

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

13. Input the DTC: P0112 or P0113.

14. Check the DTC judgment result.

    GTS Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips

    
    

    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

15. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Click here.

    Tech Tips

    
    

    • If a permanent DTC is output, the system is malfunctioning.

    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

*a	Intake Air Temperature Sensor (Mass Air Flow Meter)

CAUTION / NOTICE / HINT

PROCEDURE

1. READ VALUE USING GTS (INTAKE AIR TEMPERATURE)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Engine / Data List / Intake Air.

   5. Read the value displayed on the GTS.

      OK
      Same as actual intake air temperature.

      Result

      Result	Proceed to
      -40°C (-40°F)	A
      120°C (248°F)	B
      Same as actual intake air temperature	C

      Tech Tips

      
      

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

      • If there is a short circuit, the GTS indicates 215°C (419°F).

   
   

   B

   READ VALUE USING GTS (CHECK FOR SHORT IN WIRE HARNESS) Click here

   C

   CHECK FOR INTERMITTENT PROBLEMS Click here

   A

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

   
   
   1. 

      Text in Illustration

      *1	Mass Air Flow Meter
      *2	ECM
      *a	Front view of wire harness connector (to Mass Air Flow Meter)

      Disconnect the mass air flow meter connector.

   2. Connect terminals 1 and 2 of the mass air flow meter connector on the wire harness side.

   3. Connect the GTS to the DLC3.

   4. Turn the ignition switch to ON.

   5. Turn the GTS on.

   6. Enter the following menus: Powertrain / Engine / Data List / Intake Air.

   7. Read the value displayed on the GTS.

      Standard value
      Higher than 120°C (248°F)

   
   

   OK

   REPLACE MASS AIR FLOW METER Click here

   NG

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

   
   

   1. Disconnect the mass air flow meter connector.

   2. Disconnect the ECM connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for open)
      Tester Connection Condition Specified Condition A33-12 (THA) - C16-1 (THA) Always Below 1 Ω A36-29 (E1) - C16-2 (E2) Always Below 1 Ω

   
   

   OK

   REPLACE ECM Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

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

   
   
   1. 

      Text in Illustration

      *1	Mass Air Flow Meter
      *2	ECM

      Disconnect the mass air flow meter connector.

   2. Connect the GTS to the DLC3.

   3. Turn the ignition switch to ON.

   4. Turn the GTS on.

   5. Enter the following menus: Powertrain / Engine / Data List / Intake Air.

   6. Read the value displayed on the GTS.

      Standard value
      -40°C (-40°F)

   
   

   OK

   REPLACE MASS AIR FLOW METER Click here

   NG

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

   
   

   1. Disconnect the mass air flow meter connector.

   2. Disconnect the ECM connector.

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition A33-12 (THA) or C16-1(THA) - Body ground Always 10 kΩ or higher A36-29 (E1) or C16-2 (E2) - Body ground Always 10 kΩ or higher

   
   

   OK

   REPLACE ECM Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR