DTC P0113: Intake Air Temperature Circuit High Input

CIRCUIT OPERATION

Approximately 5 volts are applied to the intake air temperature sensor output terminal (terminal No. 1) from the ECM (terminal No. 89) via the resistor in the ECM. The ground terminal (terminal No. 4) is grounded with ECM (terminal No. 88).
The intake air temperature sensor is a negative temperature coefficient type of resistor. When the intake air temperature rises, the resistance decreases.
The intake air temperature sensor output voltage increases when the resistance increases and decreases when the resistance decreases.

TECHNICAL DESCRIPTION

The intake air temperature sensor 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

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

Judgement Criterion

Intake air temperature sensor 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.

OBD-II DRIVE CYCLE PATTERN

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

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

DIAGNOSIS

Required Special Tools:

MB991958: Scan Tool (M.U.T.-III Sub Assembly)

MB991824: V.C.I.
MB991827: USB Cable
MB991910: Main Harness A

MB992110: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check data list item 5: Intake Air Temperature Sensor.

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 5, Intake Air Temperature Sensor.

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?

It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Go to Step 2.

STEP 2. Check harness connector A-05 at the intake air temperature sensor for damage.

Q. Is the harness connector in good condition?

	Go to Step 3.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 10.

STEP 3. Check the intake air temperature sensor.

(1)Disconnect the intake air temperature sensor connector A-05.

(2)Measure the resistance between intake air temperature sensor side connector terminal No. 1 and No. 4.

There should be continuity. (0.31 - 17 kΩ)

Q. Is the measured resistance between 0.31 and 17 kΩ?

Go to Step 4.

Replace the mass airflow sensor. Then go to Step 10.

STEP 4. Measure the sensor supply voltage at intake air temperature sensor harness side connector A-05.

(1)Disconnect the connector A-05 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 7.

Go to Step 5.

STEP 5. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

	Go to Step 6.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 10.

STEP 6. 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 connector A-05.
(3)Turn the ignition switch to the "ON" position.

(4)Measure the voltage between terminal No. 89 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?

Repair harness wire between intake air temperature sensor connector A-05 (terminal No. 1) and ECM connector B-109 (terminal No. 89) because of open circuit. Then go to Step 10.

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

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

. Then go to Step 10.

STEP 7. Check the continuity at intake air temperature sensor harness side connector A-05.

(1)Disconnect the connector A-05 and measure at the harness side.

(2)Check for the continuity between terminal No. 4 and ground.

Continuity (2 Ω 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 Judgment Table <Vehicles with KOS>

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

. Then go to Step 10.

Go to Step 8.

STEP 8. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

	Go to Step 9.

	Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 10.

STEP 9. Check for open circuit between intake air temperature sensor connector A-05 (terminal No. 4) and ECM connector B-109 (terminal No. 88).

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 Judgment Table <Vehicles with KOS> or GROUP 42C, Diagnosis - ID Codes Registration Judgment Table <Vehicles with WCM> . Then go to Step 10.

	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

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

Q. Is DTC P0113 set?

	Retry the troubleshooting.

	The inspection is complete.