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DTC P0113: Intake Air Temperature Circuit High Input
 
 
 
 
CIRCUIT OPERATION
  • Approximately 5 volts are applied to the intake air temperature sensor output terminal from the ECM terminal ATS via the resistor in the ECM. The ground terminal is grounded with ECM terminal AFSE.
  • 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
  • Intake air temperature sensor 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.
Judgment 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.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Control as if the intake air temperature is 25°C (77°F).
  • Engine output is restricted
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 .
 
 
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:
  • MB992744: Vehicle Communication Interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite Main Harness A
  • MB992747: V.C.I.-Lite USB Cable Short
  • MB992748: V.C.I.-Lite USB Cable Long
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: Vehicles Communication Interface (V.C.I.)
    • MB991827: M.U.T.-III USB Cable
    • MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
  • MB992110: Power Plant ECU Check Harness
STEP 1. Using scan tool (M.U.T.-III), check data list item 5: Intake Air Temperature Sensor.
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
(1) Connect scan tool (M.U.T.-III). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) .
(2) Turn the ignition switch to the "ON" position.
(3) Set scan tool (M.U.T.-III) 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.
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 the intake air temperature sensor.
Refer to Intake Air Temperature Sensor Check .
Is the measured resistance at the standard value?
Go to Step 3.
Replace the mass airflow sensor. Then go to Step 7.
 
STEP 3. Measure the sensor supply voltage at intake air temperature sensor harness side connector.
(1) Disconnect the mass airflow sensor connector and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal power supply line and ground.
  • Voltage should be between 4.5 and 4.9 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 4.5 and 4.9 volts?
Go to Step 5.
Go to Step 4.
 
STEP 4. Measure the sensor supply voltage at ECM connector 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 mass airflow sensor connector and measure at mass airflow sensor side.
(3) Turn the ignition switch to the "ON" position.
(4) Measure the voltage between terminal ATS and ground.
  • Voltage should be between 4.5 and 4.9 volts.
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 4.5 and 4.9 volts?
Repair or replace the connector(s), or check and repair the harness of open circuit in ATS line between mass airflow sensor connector and ECM connector. Then go to Step 8.
Go to Step 7.
 
STEP 5. Check the continuity at intake air temperature sensor harness side connector.
(1) Disconnect the mass airflow sensor connector and measure at the harness side.
(2) Check for the continuity between terminal AFSE line and ground.
  • Continuity (2 ohms or less)
Does continuity exist?
Go to Step 7.
Go to Step 6.
 
STEP 6. Check of open circuit in AFSE line between mass airflow sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 7.
Repair the connector(s) or wiring harness. Then go to Step 8.
 
STEP 7. Using scan tool (M.U.T.-III), check data list item 5: Intake Air Temperature Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool (M.U.T.-III) 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.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
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 .
Replace the ECM (Refer to Removal and Installation ). Then go to Step 8.
 
STEP 8. 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).
Is DTC P0113 set?
Retry the troubleshooting.
The inspection is complete.