P0098

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

Intake air temperature sensor 2 output voltage is out of specified range.

MONITOR EXECUTION

Continuous

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

- 2 seconds or more have passed since the engine starting sequence was completed.
Judgement Criterion

- Intake air temperature sensor 2 output voltage has continued to be 4.6 volts or higher [corresponding to an intake air temperature of -40°C (-40°F) or lower] for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

- Control as if the intake air temperature in the intake manifold is 25° C.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes .

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. Using scan tool MB991958, check data list item DE:
Intake Air Temperature Sensor 2.





CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool MB991958.

(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to the data reading mode for item DE, Intake Air Temperature Sensor 2.

- The intake air temperature and temperature shown with the scan tool should approximately match.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the sensor operating properly?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

NO Go to Step 2.

STEP 2. Check harness connector B-16 at the intake air temperature sensor 2 for damage.

Q. Is the harness connector in good condition?

YES Go to Step 3.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.
STEP 3. Check the intake air temperature sensor 2.

(1)Disconnect the intake air temperature sensor 2 connector B-16.





(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 kohms)

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

YES Go to Step 4.

NO Replace the intake air temperature sensor 2. Then go to Step 10.

STEP 4. Measure the sensor supply voltage at intake air temperature sensor 2 harness side connector B-16.

(1)Disconnect the connector B-16 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?

YES Go to Step 7.

NO Go to Step 5.

STEP 5. Check harness connector B-10 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 6.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.
STEP 6. Measure the sensor supply voltage at ECM connector B-10 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-16.
(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?

YES Check harness connector A-13 at intermediate connector for damage, and repair or replace as required. Harness Connector Inspection.
If intermediate connector is in good condition, repair harness wire between intake air temperature sensor 2 connector B-16 (terminal No. 1) and ECM connector B-10 (terminal No. 98) because of open circuit. Then go to Step 10.

NO Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 10.

STEP 7. Check the continuity at intake air temperature sensor 2 harness side connector B-16.

(1)Disconnect the connector B-16 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?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 10.

NO Go to Step 8.

STEP 8. Check harness connector B-10 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 9.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 10.
STEP 9. Check for open circuit between intake air temperature sensor 2 connector B-16 (terminal No. 2) and ECM connector B-10 (terminal No. 97).

NOTE:
Check harness after checking intermediate connector A-13. If intermediate connector is damaged, repair or replace it. Repair to Harness Connector Inspection Harness Connector Inspection.
Then go to Step 10.

Q. Is the harness wire in good condition?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 10.
NO Repair it. Then go to Step 10.
STEP 10. 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 Monitors, Trips, Drive Cycles and Readiness Codes.

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

Q. Is DTC P0098 set?

YES Retry the troubleshooting.
NO The inspection is complete.