Toyota Corolla Repair Manual: Circuit description
The intake air temperature (iat) sensor, mounted on the mass air flow (maf) sensor, 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 fig. 1).
The intake air temperature sensor is connected to the ecm.
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 potential at terminal tha (thar) also changes. Based on this signal, the ecm increases the fuel injection volume to improve the drive ability during cold engine operation.
|
Dtc no. |
Proceed to |
Dtc detection condition |
Trouble area |
| P0110 | Step 1 | Open or short in intake air temperature sensor circuit for 0.5 Seconds |
|
| P0112 | Step 4 | Short in intake air temperature sensor circuit for 0.5 Seconds | |
| P0113 | Step 2 | Open in intake air temperature sensor circuit for 0.5 Seconds |
Hint
: after confirming dtc p0110, p0112 or p0113, confirm the intake air temperature in the ”diagnosis / enhanced obd ii / data list / all” using the hand–held tester or the obd ii scan tool.
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 equal to –40 c (–40 °F) or more than 140 c (284 °F).
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating range
Wiring diagram
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 ...
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
Read freeze frame data using the hand-h ...
Other materials:
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove parking brake hole cover sub–assy
4. Remove floor shift shift lever knob sub–assy (m/t transaxle)
5. Remove shifting hole cover sub–assy (m/t transaxle)
6. Remove console panel upper
7. Remove console box ...
Malfunction in tachometer
Wiring diagram
Inspection procedure
Check output value of ecm.
Connect the hand–held tester to dlc3.
Turn the ignition switch to on and push the hand–held tester main switch
on.
Select the data list mode on the hand–held tester.
2 Inspect combination mete ...
Front differential oil seal (atm)
Replacement
1. Remove front wheels
2. Remove engine under cover rh
3. Remove engine under cover lh
4. Drain automatic transaxle fluid
remove the drain plug, gasket and drain atf.
install a new gasket and drain plug.
Torque: 17.5 Nvm (178 Kgf·cm, 13 ft·lbf)
5. Remove front ...