P0113

2GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0112,P0113: Intake Air Temperature Circuit Low Input
P0113 - Intake Air Temperature Circuit High Input

DESCRIPTION





- The Intake Air Temperature (IAT) sensor, mounted on the Mass Air Flow (MAF) meter, monitors the IAT. The IAT sensor has a built in thermistor with a resistance that varies according to the temperature of the intake air. When the IAT 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 IAT sensor is powered by a 5 V supply from the THA terminal of the ECM, via resistor R.

- Resistor R and the IAT sensor are connected in series. When the resistance value of the IAT sensor changes, according to changes in the IAT, 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.

HINT
When any of DTCs P0112 and P0113 are set, the ECM enters fail-safe mode. During fail-safe mode, the IAT 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 IAT by selecting the following menu items on the Techstream: Powertrain / Engine / Data List / Intake Air.





MONITOR DESCRIPTION

The ECM monitors the sensor voltage and uses this value to calculate the Intake Air Temperature (IAT). When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a malfunction in the IAT 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 IAT 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





CONFIRMATION DRIVING PATTERN





- Connect the Techstream to the DLC3.

- Turn the engine switch on (IG) and turn the Techstream on.

- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) DTC Check / Clear.

- Turn the engine switch off and wait for 30 seconds.

- Turn the engine switch on (IG) and turn the Techstream on.

- Wait 0.5 seconds or more [A].

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

- Read the DTC [B].

HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.

- Input the DTC: P0112 or P0113.

- Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or UNKNOWN, perform step [A] again.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.

- Check the DTC judgment result.

HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the test result is INCOMPLETE or UNKNOWN and no 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





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 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 VALUE USING TECHSTREAM (INTAKE AIR)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Select the following menu items: Powertrain / Engine / Data List / Intake Air.

(e) Read the value displayed on the Techstream.

Standard:

Same as actual Intake Air Temperature (IAT).

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) or higher.
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 E83 MAF meter connector.





(b) Connect terminals THA and E2 of the MAF meter wire harness side connector.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Select the following menu items: Powertrain / Engine / Data List / Intake Air.

(g) Read the value displayed on the Techstream.

Standard:

140°C (284°F) or higher

(h) Reconnect the MAF meter connector.

OK -- CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER
NG -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

(a) Disconnect the E83 MAF meter connector.

(b) Disconnect the E6 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





(d) Reconnect the MAF connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM

4. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)

(a) Disconnect the E83 MAF meter connector.





(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Select the following menu items: Powertrain / Engine / Data List / Intake Air.

(f) Read the value displayed on the Techstream.

Standard:

-40°C (-40°F) or higher

(g) Reconnect the MAF meter connector.

OK -- REPLACE MASS AIR FLOW METER
NG -- Continue to next step.

5. READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN ECM)

(a) Disconnect the E83 MAF meter connector.

(b) Disconnect the E6 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for short):





(d) Reconnect the MAF connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM