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P0110








1NZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0110: Intake Air Temperature Circuit

DTC P0110 - Intake Air Temperature Circuit

DTC P0112 - Intake Air Temperature Circuit Low Input

DTC P0113 - Intake Air Temperature Circuit High Input

DESCRIPTION





The intake air temperature (IAT) sensor, mounted on the mass air flow (MAF) meter, monitors the intake air temperature. The IAT sensor has a thermistor that varies its resistance depending on the temperature of the intake air. When the air temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. The variations in resistance are reflected as voltage changes to the ECM terminal (see Figure 1).
The intake air temperature sensor is connected to the ECM (see wiring diagram). The 5 V power source voltage in the ECM is applied to the intake air temperature sensor from terminal THA (THAR) via resistor R.
That is, the resistor R and the intake air temperature sensor are connected in series. When the resistance value of the intake air temperature sensor changes in accordance with changes in the intake air temperature, the voltage at terminal THA (THAR) also changes. Based on this signal, the ECM increases the fuel injection volume to improve the driveability during cold engine operation.





HINT: After confirming DTC P0110, P0112 or P0113, confirm the intake air temperature in Powertrain / Engine and ECT / Data List / Intake Air using Techstream.





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 fault in the IAT sensor and sets a DTC.
Example:
When the sensor voltage output is equal to -40°C (-40°F), or more than 140°C (284°F), and either condition continues for 0.5 seconds or more.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0110: Intake air temperature sensor range check (fluttering)





P0112: Intake air temperature sensor range check (low resistance)





P0113: Intake air temperature sensor range check (high resistance)





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
- If DTCs related 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 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 Freeze Frame Data.

PROCEDURE

1. READ OUTPUT DTC
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG) and turn Techstream ON.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(d) Read the DTCs.
Result:






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

2. READ VALUE USING TECHSTREAM (INTAKE AIR TEMPERATURE)
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Turn Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
(e) Read the value.
Temperature value:
Same as the ambient air temperature.
Result:





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

3. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)




(a) Disconnect the M1 mass air flow meter connector.




(b) Connect terminals THA and E2 of the mass air flow meter wire harness side connector.
(c) Turn the power switch ON (IG).
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air. Read the value.
OK:
Temperature value: 140°C (284°F)
(e) Reconnect the mass air flow meter connector.
OK -- CONFIRM GOOD CONNECTION AT SENSOR. IF OK, REPLACE MASS AIR FLOW METER
NG -- Continue to next step.

4. READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN ECM)




(a) Disconnect the M1 mass air flow meter connector.




(b) Connect terminals THA and E2 of the E4 ECM connector.
HINT: Before checking, do a visual and contact pressure check for the ECM connector.
(c) Turn the power switch ON (IG).
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air. Read the value.
OK:
Temperature value: 140°C (284°F)
(e) Reconnect the mass air flow meter connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
NG -- CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM
5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)




(a) Disconnect the M1 mass air flow meter connector.
(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
(d) Read the value.
OK:
Temperature value: -40°C (-40°F)
(e) Reconnect the mass air flow meter connector.
OK -- REPLACE MASS AIR FLOW METER
NG -- Continue to next step.

6. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)
(a) Disconnect the E4 ECM connector.








(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Engine and ECT / Data List / Intake Air.
(d) Read the value.
OK:
Temperature value: -40°C (-40°F)
(e) Reconnect the mass air flow meter connector.
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR
NG -- REPLACE ECM
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