Toyota RAV4 manuals

Toyota Sienna Service Manual: Intake Air Temperature Sensor Gradient Too High

Intake Air Temperature Sensor Gradient Too High

DESCRIPTION

Intake Air Temperature Sensor Gradient Too High

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 becomes low, the resistance of the thermistor increases. When the temperature becomes 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 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.

Intake Air Temperature Sensor Gradient Too High

MONITOR DESCRIPTION

The ECM performs OBD II monitoring based on the values from the intake air temperature sensor. If there is no change in the sensor value, the ECM will not be able to perform OBD II monitoring or will misdiagnose that there is a malfunction in the sensor. The ECM detects the stuck intake air temperature sensor value by performing monitoring after the ignition switch is turned off or the ignition is started (short soak or long soak).

MONITOR STRATEGY

MONITOR STRATEGY

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

TYPICAL MALFUNCTION THRESHOLDS

WIRING DIAGRAM

Refer to DTC P0110 (See page ES-126).

INSPECTION PROCEDURE

1 CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0111)

(a) Connect the intelligent tester to the DLC3.

(b) Turn the ignition switch to the ON position.

(c) Turn the tester on.

(d) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

(e) Read the DTCs.

Result

HINT: If any DTCs other than P0111 are output, troubleshoot those DTCs first.

GO TO DTC CHART (See page ES-56)

Intake Air Temperature Circuit
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 accord ...

Engine Coolant Temperature Circuit
DESCRIPTION A thermistor is built into the Engine Coolant Temperature (ECT) sensor, of which the resistance value varies according to the ECT. The structure of the sensor and its connection ...

Other materials:

How to proceed with troubleshooting
The intelligent tester can be used at steps 3, 7, 10, and 13. 1 VEHICLE BROUGHT TO WORKSHOP 2 CUSTOMER PROBLEM ANALYSIS (a) Interview the customer to confirm the trouble. 3 DTC CHECK/CLEAR AND FREEZE FRAME DATA 4 PROBLEM SYMPTOM CONFIRMATION 5 PROBLEM SYMPTOM SIMULATION 6 SYMPTOM SI ...

On-vehicle inspection
1. INSPECT CURTAIN SHIELD AIRBAG ASSEMBLY (VEHICLE NOT INVOLVED IN COLLISION)  Perform a diagnostic system check.  With the curtain shield airbag assembly installed on the vehicle, perform a visual check. If there are any defects as mentioned below, replace the front pillar ...

Room temperature sensor
On-vehicle inspection 1. INSPECT A/C ROOM TEMPERATURE SENSOR (a) Remove the A/C room temperature sensor. (b) Measure the resistance according to the value(s) in the table below. Standard resistance NOTICE: Even slightly touching the sensor may change the resistance value. Be sure ...

В© 2011-2021 Copyright www.tsienna.net