P0111

2AR-FE ENGINE CONTROL: SFI SYSTEM: P0111: Intake Air Temperature Sensor Gradient Too High
P0111 - Intake Air Temperature Sensor Gradient Too High

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 (See Fig. 1).

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

- Resistor R 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.





MONITOR DESCRIPTION

The ECM performs OBD II monitoring based on the values from the intake air temperature sensor. If there is no change of the sensor value within the normal range, the ECM will not be able to perform OBD II monitoring or will misdiagnose that there is a malfunction in the sensor. The ECM detects when the intake air temperature sensor value is stuck by performing monitoring after the ignition switch is turned off or the engine is started (short soak or long soak).

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





After Engine Stop





After Cold Engine Start





TYPICAL MALFUNCTION THRESHOLDS

After Engine Stop





After Cold Engine Start





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

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

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

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

5. Turn the ignition switch to ON and turn the Techstream on [A].

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

7. Idle the engine for 5 minutes or more [C].

HINT
During steps [A] through [C], if the change in the intake air temperature is less than 1°C (1.8°F), the intake air temperature sensor (mass air flow meter assembly) is malfunctioning. It is not necessary to continue this procedure.

8. Enter the following menus: Powertrain / Engine / Trouble Codes [D].

9. Read the pending DTCs.

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

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

11. Input the DTC: P0111.

12. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [E] and [F].

13. Drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more [E].

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

14. Check the DTC judgment result again [F].

HINT
If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [E] and [F] again.

15. If no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.

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

WIRING DIAGRAM

Refer to DTC P0112 P0112.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0111)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

Result





HINT
If any DTCs other than P0111 are output, troubleshoot those DTCs first.

B -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal

A -- GO TO DTC CHART Engine Control - SFI System