DTC P0098: Intake Air Temperature Circuit High Input (sensor 2)

CIRCUIT OPERATION

Approximately 5 volts are applied to the intake air temperature sensor 2 output terminal (terminal No. 1) from the ECM (terminal No. 98) via the resistor in the ECM. The ground terminal (terminal No. 2) is grounded with ECM (terminal No. 97).
The intake air temperature sensor 2 is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
The intake air temperature sensor 2 output voltage increases when the resistance increases and decreases when the resistance decreases.

TECHNICAL DESCRIPTION

The intake air temperature sensor 2 converts the intake air temperature to a voltage.
The ECM checks whether this voltage is within a specified range.

DESCRIPTIONS OF MONITOR METHODS

MONITOR EXECUTION

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

Not applicable

Sensor (The sensor below is determined to be normal)

Not applicable

DTC SET CONDITIONS

Logic Flow Chart

Check Condition

More than 2 seconds have passed since the engine starting sequence was completed.

Judgement Criterion

Intake air temperature sensor 2 output voltage is more than 4.6 volts [corresponding to an intake air temperature of -40°C (-40°F) or less] for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

Control as if the intake air temperature in the intake manifold is 25 °C (77°F).

OBD-II DRIVE CYCLE PATTERN

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )

Intake air temperature sensor 2 failed.
Open intake air temperature sensor 2 circuit, or connector damage.
ECM failed.

DIAGNOSIS

Required Special Tools

MB992110: Power Plant ECU Check Harness

STEP 1. Check harness connector B-20 at intake air temperature sensor 2 for damage.

Q. Is the harness connector in good condition?

	Go to Step 2.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 9.

STEP 2. Check the intake air temperature sensor 2.

(1)Disconnect the intake air temperature sensor 2 connector B-20.

(2)Measure the resistance between intake air temperature sensor 2 side connector terminal No. 1 and No. 2.

There should be continuity. (0.23 - 18 kΩ)

Q. Is the measured resistance between 0.23 and 18 kΩ?

Go to Step 3.

Replace the intake air temperature sensor 2. Then go to Step 9.

STEP 3. Measure the sensor supply voltage at intake air temperature sensor 2 harness side connector B-20.

(1)Disconnect the connector B-20 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.

(3)Measure the voltage between terminal No. 1 and ground.

Voltage should be between 4.5 and 4.9 volts.

(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the measured voltage between 4.5 and 4.9 volts?

Go to Step 6.

Go to Step 4.

STEP 4. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

	Go to Step 5.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 9.

STEP 5. Measure the sensor supply voltage at ECM connector B-109 by using power plant ECU check harness special tool MB992110.

(1)Disconnect all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2)Disconnect the intake air temperature sensor 2 connector B-20.
(3)Turn the ignition switch to the "ON" position.

(4)Measure the voltage between terminal No. 98 and ground.

Voltage should be between 4.5 and 4.9 volts.

(5)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the measured voltage between 4.5 and 4.9 volts?

Check harness connector A-54 at intermediate connector for damage, and repair or replace as required. Refer to GROUP 00E, Harness Connector Inspection

. If intermediate connector is in good condition, repair harness wire between intake air temperature sensor 2 connector B-20 (terminal No. 1) and ECM connector B-109 (terminal No. 98) because of open circuit. Then go to Step 9.

Replace the ECM. When the ECM is replaced, register the ID code. Refer to GROUP 42B, Diagnosis - ID Code Registration Necessity Judgment Table <Vehicles with KOS>

or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM>

. Then go to Step 9.

STEP 6. Check the continuity at intake air temperature sensor 2 harness side connector B-20.

(1)Disconnect the connector B-20 and measure at the harness side.

(2)Check for the continuity between terminal No. 2 and ground.

Continuity (2 ohms or less)

Q. Does continuity exist?

Replace the ECM. When the ECM is replaced, register the ID code. Refer to GROUP 42B, Diagnosis - ID Code Registration Necessity Judgment Table <Vehicles with KOS>

or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM>

. Then go to Step 9.

Go to Step 7.

STEP 7. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

	Go to Step 8.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 9.

STEP 8. Check for open circuit between intake air temperature sensor 2 connector B-20 (terminal No. 2) and ECM connector B-109 (terminal No. 97).

note

Check harness after checking intermediate connector A-54. If intermediate connector is damaged, repair or replace it. Refer to GROUP 00E, Harness Connector Inspection

. Then go to Step 9.

Q. Is the harness wire in good condition?

	Replace the ECM. When the ECM is replaced, register the ID code. Refer to GROUP 42B, Diagnosis - ID Code Registration Necessity Judgment Table <Vehicles with KOS> or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM> . Then go to Step 9.

	Repair it. Then go to Step 9.

STEP 9. Test the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0098 set?

	Retry the troubleshooting.

	The inspection is complete.