DI76 EINE (1ZZFE) DI37Z12 DTC P0110 Circuit Malfunction CIRCUIT DESCRIPTI Resistance KΩ (Fig.1) 30 20 10 5 3 2 1 0.5 0.3 0.2 0.1 Acceptable 20 0 20 40 60 80 100 ( 4) 32 68 104 140 176 212 Temp. C ( F) The intake air temperature (IAT) sensor, mounted on the mass air flow (MAF) meter, 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 terminal. (See Fig. 1). The intake air temperature sensor is connected to the. The 5 V power source voltage in the is applied to the intake air temperature sensor from terminal 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 the intake air temperature, the potential at terminal also changes. Based on this signal, the increases the fuel injection volume to improve the drive ability during cold engine operation. A21412 DTC No. DTC Detecting Condition Trouble Area P0110 Open or short in intake air temperature sensor circuit Open or short in intake air temp. sensor circuit Intake air temperature sensor (built into mass air flow meter) After confirming DTC P0110, confirm the intake air temperature in the DIAGNOSIS / ENHANCED OBD ll / DATA LIST / ALL using the handheld tester or OBD ll scan tool. Temperature Displayed 40 C (40 F) Malfunction Open circuit 140 C (284 F) or more Short circuit MITOR DESCRIPTI The 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 interprets this as a fault in the IAT (Intake Air Temperature) sensor and sets a DTC. Example: When the sensor voltage output equal to 40 C (40 F), or more than 140 C (284 F). 274
EINE (1ZZFE) DI77 MITOR STRATEGY Related DTCs Required sensors/components Frequency of operation Duration MIL operation Sequence of operation P0110 Intake air temperature sensor Continuous 0.5 sec. Immediate None Intake air temperature sensor range check (Low or high voltage) TYPICAL ENABLI CDITIS The monitor will run whenever the following DTCs are not present The typical enabling condition is not available See List of disable a monitor (on page DI3) TYPICAL MALFUNCTI THRESHOLDS Detection Criteria Intake air temperature sensor resistance (Intake air temperature) Threshold Less than 98.5 Ω, or more than 156 kω (More than 140 C (284 F), or less than 40 C (40 F)) COMPENT OPERATI RAE Parameter Intake air temperature sensor resistance Standard Value 98.5 Ω (140 C (284 F)) to 156 kω (40 C (40 F)) WIRI DIAGRAM M1 Intake Air Temperature (Built into mass air flow meter) 4 LR 22 R 5 BR A00310 275
DI78 EINE (1ZZFE) INSPECTI PROCEDURE If different DTCs related to different systems that have terminal as the ground terminal are output simultaneously, terminal may be open. Read freeze frame data using the handheld tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the airfuel ratio was lean or rich, as well as other data from the time when a malfunction occurred. 1 Connect OBD II scan tool or handheld tester, and read value of intake air temperature. (a) Connect the handheld tester or the OBD II scan tool to the DLC3. (b) Turn the ignition switch and push the handheld tester or the OBD II scan tool main switch. (c) When using handheld tester, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL Read temperature value displayed on the handheld tester or the OBD II scan tool. Same as the actual intake air temperature and temperature displayed on the handheld tester or OBD II scan tool. RESULT: Temperature Displayed 40 C (40 F) Proceed to 140 C (284 F) or more B OK (Same as present temperature) If there is an open circuit, the handheld tester or the OBD II scan tool indicates 40 C (40 F). If there is a short circuit, the handheld tester or the OBD II scan tool indicates 140 C (284 F) or more. A C B Go to step 4. C Check for intermittent problems (See page DI3). A 276
EINE (1ZZFE) DI79 2 Check for open in harness or. 2 1 22 A00391 (a) Disconnect the intake temp. sensor connector. (b) Connect sensor wire harness terminals together. (c) Turn the ignition switch. (d) When using handheld tester, enter the following menus: Read temperature value on the OBD II scan tool or the hand held tester. Temperature value: 140 C (284 F) or more OK Confirm good connection at sensor. If OK, replace intake air temperature sensor. 277
DI80 EINE (1ZZFE) 3 Check for open in harness or. 22 (a) Remove the cover. (b) Connect between terminals and of the connector. In take air temp. sensor connector is disconnected. Before checking, do a visual and contact pressure checks for the connector (See page IN30). (c) Turn the ignition switch. (d) When using handheld tester, enter the following menus: Read temperature value on the OBD II scan tool or handheld tester. Temperature value: 140 C (284 F) or more A09084 A11408 OK Repair or replace harness or connector. Confirm good connection at. If OK, replace (See page SF78). 278
EINE (1ZZFE) DI81 4 Check for short in harness and. 2 1 A00393 22 (a) Disconnect the mass air flow meter connector. (b) Turn the ignition switch. (c) When using handheld tester, enter the following menus: Read temperature value on the OBD II scan tool or handheld tester. Temperature value: 40 C (40 F) OK Replace mass air flow meter. 279
DI82 EINE (1ZZFE) 5 Check for short in harness or. (a) Remove the cover. (b) Disconnect the connector of the. Intake air temp. sensor connector is disconnected. (c) Turn the ignition switch. (d) When using handheld tester, enter the following menus: Read temperature value on the OBD II scan tool or handheld tester. Temperature value: 40 C (40 F) Connector A09085 A09091 OK Repair or replace harness or connector. Replace (See page SF78). 280