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:
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished). Perform active test using
hand–held tester (a/f
control).
Perform active test using the hand–held tester (a ...
Bluetooth® (Multimedia system)
Bluetooth®
■When using the Bluetooth® audio system
●In the following conditions, the system may not function.
• If the portable audio player is turned off
• If the portable audio player is not connected
• If the portable audio player’s battery is low
●There may be a delay if ...
Inspection procedure
Hint:
read freeze frame data using the hand–held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...