P0113

2UR-GSE ENGINE CONTROL: SFI SYSTEM: P0112: Intake Air Temperature Circuit Low Input

DTC P0112 - Intake Air Temperature Circuit Low Input

DTC P0113 - Intake Air Temperature Circuit High Input

DESCRIPTION





The intake air temperature sensor, in 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 drivability.
HINT: When any of DTCs P0112 and P0113 are set, 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.





HINT: When any of these DTCs are set, check the intake air temperature by entering the following menus: Powertrain / Engine / Data List / Intake Air.





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 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 intake air temperature 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





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
- If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- 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 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.

PROCEDURE

1. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)
(a) Connect the 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 / Intake Air.
(e) Read the value displayed on the Techstream.
Standard:
Same as actual intake air temperature.
Result:





HINT:
- If there is an open circuit, the Techstream indicates -40°C (-40°F).
- If there is a short circuit, the Techstream indicates 140°C (284°F).

C -- CHECK FOR INTERMITTENT PROBLEMS
B -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)





(a) Disconnect the mass air flow meter connector.
(b) Connect terminals THA and E2 of the mass air flow meter wire harness connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn the Techstream ON.
(f) Enter the following menus: Powertrain / Engine / Data List / Intake Air.
(g) Read the value displayed on the Techstream.
Standard:
140°C (284°F)
(h) Reconnect the mass air flow meter connector.
NG -- READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)
OK -- REPLACE MASS AIR FLOW METER
3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)





(a) Disconnect the mass air flow meter connector.
(b) Connect terminals THA and E2 of the ECM connector.
HINT: Before checking, do visual and contact pressure checks on the ECM connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn the Techstream ON.
(f) Enter the following menus: Powertrain / Engine / Data List / Intake Air.
(g) Read the value displayed on the Techstream.
Standard:
140°C (284°F)
(h) Reconnect the mass air flow meter connector.
NG -- REPLACE ECM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
4. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)





(a) Disconnect the mass air flow meter connector.
(b) Connect the 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 / Intake Air.
(f) Read the value displayed on the Techstream.
Standard:
-40°C (-40°F)
(g) Reconnect the mass air flow meter connector.
NG -- READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
OK -- REPLACE MASS AIR FLOW METER
5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)





(a) Disconnect the mass air flow meter connector.
(b) Disconnect the ECM connector.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn the Techstream ON.
(f) Enter the following menus: Powertrain / Engine / Data List / Intake Air.
(g) Read the value displayed on the Techstream.
Standard:
-40°C (-40°F)
(h) Reconnect the mass air flow meter connector.
NG -- REPLACE ECM
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR