Dtc P0110 Intake Air Temperature Circuit Malfunction
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)
READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
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 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, the voltage at terminal THA varies accordingly. Based on this signal, the ECM increases the fuel injection volume when the engine is cold to improve driveability.
- УКАЗАНИЕ:
- 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 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 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 IAT sensor circuit for 0.5 seconds (1 trip detection logic)
| - Open in IAT sensor circuit
- IAT sensor (built into MAF meter)
- ECM
|
- УКАЗАНИЕ:
- When any of these DTCs are set, check the IAT by selecting the following menu items on the intelligent tester: Powertrain / Engine and ECT / 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
- УКАЗАНИЕ:
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE) |
Connect the intelligent tester to the DLC3.
Turn the ignition switch on (IG) and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / 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
|
- УКАЗАНИЕ:
- 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 |
|
|
2.READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) |
Disconnect the B1 Mass Air Flow (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 on (IG) and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Data List / Intake Air.
Read the value displayed on the tester.
- Standard:
- 140°C (284°F) or higher
Reconnect the MAF meter connector.
| CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER |
|
|
3.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
Disconnect the B1 MAF meter connector.
Disconnect the B32 ECM connector.
Measure the resistance.
- Standard resistance:
Tester Connection
| Specified Condition
|
THA (B1-1) - THA (B32-65)
| Below 1 Ω
|
E2 (B1-2) - ETHA (B32-88)
|
Reconnect the MAF meter connector.
Reconnect the ECM connector.
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
OK |
|
|
|
CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM |
|
4.READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) |
Disconnect the B1 MAF meter connector.
Connect the intelligent tester to the DLC3.
Turn the ignition switch on (IG) and turn the tester ON.
Select the following menu items: Powertrain / Engine and ECT / Data List / Intake Air.
Read the value displayed on the tester.
- Standard:
- -40°C (-40°F)
Reconnect the MAF meter connector.
| REPLACE MASS AIR FLOW METER |
|
|
5.CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) |
Disconnect the B1 MAF meter connector.
Disconnect the B32 ECM connector.
Measure the resistance.
- Standard resistance:
Tester Connection
| Specified Condition
|
THA (B1-1) or THA (B32-65) - Body ground
| 10 kΩ or higher
|
Reconnect the MAF meter connector.
Reconnect the ECM connector.
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|