P0111

FA20 ENGINE CONTROL: SFI SYSTEM: P0111; Intake Air Temperature Sensor Gradient Too High; 2013 MY FR-S [03/2012 -]
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.

* 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





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

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

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

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.

6. Check that engine coolant temperature is 30°C (86°F) or less.

7. Start the engine.

8. Perform the following the confirmation driving pattern.

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

a. Idle the engine for 10 seconds or more [A].

b. Drive the vehicle at 80 km/h (50 mph) or more for 8 minutes or more [B].

c. Stop the vehicle and idle the engine for 30 seconds or more [C].

d. Drive the vehicle at 80 km/h (50 mph) or more for 30 seconds or more [D].

e. Stop the vehicle and idle the engine for 30 seconds or more [E].

f. Drive the vehicle at 80 km/h (50 mph) or more for 30 seconds or more [F].

g. Stop the vehicle and idle the engine for 30 seconds or more [G].

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

10. Read pending DTCs.

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

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

12. Input the DTC: P0111.

13. 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.

14. 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

Refer to P0112 P0112.

INSPECTION PROCEDURE

HINT
Read freeze frame data using the 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 help determine if the vehicle was moving or stationary, 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. CHECK 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 DTCs.

Result





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

B -- REPLACE MASS AIR FLOW METER Removal

A -- GO TO DTC CHART SFI System