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DTC P040F-00: EGR temperature/Intake air temperature correlation
 
 
 
 
TECHNICAL DESCRIPTION
  • Intake air temperature sensor is built into the mass airflow sensor.
  • The ECM compares the temperature measured by the EGR temperature sensor to the temperature measured by the intake air temperature sensor and determines a malfunction when the difference is greater than the control value.
 
 
DESCRIPTIONS OF MONITOR METHODS
The ECM compares the intake air temperature sensor output with the EGR temperature sensor output when the ignition switch is ON. When the difference between them exceeds the specified value, the ECM determines that the intake air temperature sensor or the EGR temperature sensor has malfunction.
 
 
MONITOR EXECUTION
Once per driving cycle.
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Intake air temperature sensor
  • EGR temperature sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • Power supply mode of electric motor switch is ON.
  • 12V battery positive voltage is 10 volts or higher.
  • ECM is woken up in 6 hours since the engine was stopped.
  • 2 seconds or more have elapsed after the above mentioned conditions have been met.
Judgment Criterion
  • The difference between the measured value of the EGR temperature sensor when IG is ON and the measured value of the intake air temperature sensor when the IG is ON is higher than specified range and continues for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
None.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 4 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • EGR temperature sensor failed.
  • Intake air temperature sensor (built into the mass airflow sensor) failed.
  • Open/short circuit or harness damage in EGR temperature sensor circuit or loose connector contact.
  • 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
1.STEP 1. Using scan tool (M.U.T.-III SE), read the DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC other than P040F-00 is set.
Q: Is DTC other than P040F-00 set?
Perform troubleshooting for the set DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART).
 
2.STEP 2. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 950: EGR Gas Temperature
Q: Is the check result normal?
 
3.STEP 3. Perform voltage measurement at EGR temperature sensor connector terminal number 1.
  • Disconnect connector, and measure at harness side.
  • Power supply mode of electric motor switch: ON
  • Voltage between EGR temperature sensor connector terminal number 1 and ground.
OK: 4.5 to 4.9 volts
Q: Is the check result normal?
Perform troubleshooting for the EGR temperature sensor circuit [Refer to DTC P040C-00: EGR temperature sensor circuit Low DTC P040C-00: EGR temperature sensor circuit Low), and Refer to DTC P040D-00: EGR temperature sensor circuit High DTC P040D-00: EGR temperature sensor circuit High)].
 
4.STEP 4. Check harness between EGR temperature sensor connector terminal number 1 and ECM connector terminal number 48.
Check power supply line for short circuit.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
5.STEP 5. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 50: Air Temperature Sensor
Q: Is the check result normal?
Perform troubleshooting for the intake air temperature sensor circuit [Refer to DTC P0112-00: Intake Air Temperature Sensor circuit low input DTC P0112-00: Intake Air Temperature Sensor circuit low input), and Refer to DTC P0113-00: Intake Air Temperature Sensor circuit high input DTC P0113-00: Intake Air Temperature Sensor circuit high input)].
 
6.STEP 6. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 950: EGR Gas Temperature
Q: Is the check result normal?
Intermittent malfunction (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).