Dtc P0110 Intake Air Temperature Circuit Malfunction
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK DTC OUTPUT
READ VALUE USING INTAKE AIR TEMPERATURE SENSOR (INTAKE AIR)
CHECK MASS AIR FLOW METER (CHECK FOR OPEN IN SENSOR)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
CHECK MASS AIR FLOW METER (CHECK FOR SHORT IN SENSOR)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER- ECM)
DTC P0110 Intake Air Temperature Circuit Malfunction |
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 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 drops, the resistance of the thermistor increases. When the temperature rises, 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 P0110, 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.
DTC No.
| Proceed to
| DTC Detection Condition
| Trouble Area
|
P0110
| Step 1
| Open or short in Intake Air Temperature (IAT) sensor circuit for 0.5 seconds (1 trip detection logic)
| - Open or short in IAT sensor circuit
- IAT sensor (built into MAF meter)
- ECM
|
P0112
| Step 4
| Short in Intake Air Temperature (IAT) sensor circuit for 0.5 seconds (1 trip detection logic)
| - Short in IAT sensor circuit
- IAT sensor (built into MAF meter)
- ECM
|
P0113
| Step 2
| Open in Intake Air Temperature (IAT) sensor circuit for 0.5 seconds (1 trip detection logic)
| - Open in IAT sensor circuit
- IAT sensor (built into MAF meter)
- ECM
|
- HINT:
- When any of these DTCs are set, check the IAT by entering the following menus on the intelligent tester: Powertrain / Engine / Data List / Intake Air.
Temperature Displayed
| Malfunction
|
-40°C (-40°F)
| Open circuit
|
140°C (284°F) or higher
| Short circuit
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
- Read freeze frame data using the intelligent tester. 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 (CAMRY_ACV40 RM000000PDS01FX.html).
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the intelligent tester on.
Select the following menu items: Powertrain / Engine / Data List / Intake Air.
Read the DTCs.
- Result:
Display (DTC output)
| Proceed to
|
P0110
| A
|
P0112
| B
|
P0113
| C
|
2.READ VALUE USING INTAKE AIR TEMPERATURE SENSOR (INTAKE AIR) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
Read the value displayed on the tester.
- Standard:
- Same as actual Intake Air Temperature (IAT).
- Result:
Temperature Displayed
| Proceed to
|
-40°C (-40°F)
| A
|
140°C (284°F) or higher
| B
|
Same as actual IAT
| C
|
- HINT:
- If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
- If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.
| |
|
| CHECK FOR INTERMITTENT PROBLEMS |
|
|
3.CHECK MASS AIR FLOW METER (CHECK FOR OPEN IN SENSOR) |
Confirm good connection of the Mass Air Flow (MAF) meter.
Disconnect the C2 MAF meter connector.
Connect terminals THA and E2 of the MAF meter wire harness side connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
Read the value displayed on the tester.
- Standard:
- 140°C (284°F) or higher
Reconnect the MAF meter connector.
4.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
Disconnect the C2 MAF meter connector.
Disconnect the C58 (RHD) or C55 (LHD) ECM connector.
Measure the resistance between the terminals.
- Standard resistance (Check for open):
- RHD:
Tester Connection
| Specified Condition
|
THA (C58-71) - THA (C2-1)
| Below 1 Ω
|
ETHA (C58-74) - E2 (C2-2)
| Below 1 Ω
|
- LHD:
Tester Connection
| Specified Condition
|
THA (C55-71) - THA (C2-1)
| Below 1 Ω
|
ETHA (C55-74) - E2 (C2-2)
| Below 1 Ω
|
- Standard resistance (Check for short):
- RHD:
Tester Connection
| Specified Condition
|
THA (C58-71) or THA (C2-1) - Body ground
| 10 kΩ or higher
|
ETHA (C58-74) or E2 (C2-2) - Body ground
| 10 kΩ or higher
|
- LHD:
Tester Connection
| Specified Condition
|
THA (C55-71) or THA (C2-1) - Body ground
| 10 kΩ or higher
|
ETHA (C55-74) or E2 (C2-2) - Body ground
| 10 kΩ or higher
|
Reconnect the MAF meter connector.
Reconnect the ECM connector.
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
5.CHECK MASS AIR FLOW METER (CHECK FOR SHORT IN SENSOR) |
Disconnect the C2 MAF meter connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
Enter the following menus: Powertrain / Engine / Data List / Intake Air.
Read the value displayed on the tester.
- Standard:
- -40°C (-40°F) or higher
Reconnect the MAF meter connector.
6.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER- ECM) |
Disconnect the C2 MAF meter connector.
Disconnect the C58 (RHD) or C55 (LHD) ECM connector.
Measure the resistance between the terminals.
- Standard resistance:
- RHD:
Tester Connection
| Specified Condition
|
THA (C58-71) or THA (C2-1) - Body ground
| 10 kΩ or higher
|
- LHD:
Tester Connection
| Specified Condition
|
THA (C55-71) or THA (C2-1) - Body ground
| 10 kΩ or higher
|
Reconnect the MAF meter connector.
Reconnect the ECM connector.
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|