P0111

2GR-FE ENGINE CONTROL SYSTEM: 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 becomes low, the resistance of the thermistor increases. When the temperature becomes 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 in the sensor value, 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 the stuck intake air temperature sensor value by performing monitoring after the ignition switch is turned off or the ignition 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:





WIRING DIAGRAM

Refer to DTC P0110 P0110.

INSPECTION PROCEDURE

PROCEDURE

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

(a) Connect the Techstream to the DLC3.

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

(c) Turn the tester on.

(d) Select the following menu items: Powertrain / Engine and ECT / Trouble Code.

(e) Read the DTCs.

Result:





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

B -- REPLACE MASS AIR FLOW METER Components

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