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DTC P040C-00: EGR temperature sensor circuit Low
 
 
 
 
CIRCUIT OPERATION
  • A power voltage of 5 volts is applied to the EGR temperature sensor connector terminal number 1 from the ECM connector terminal number 48.
  • The power voltage is grounded to the ECM connector terminal number 58 from the EGR temperature sensor connector terminal number 2.
 
 
TECHNICAL DESCRIPTION
  • The EGR temperature sensor converts the exhaust gas temperature into voltage and inputs it in the ECM.
  • The ECM controls how far the EGR valve opens based on this signal.
 
 
DESCRIPTIONS OF MONITOR METHODS
The EGR temperature sensor is a kind of resistor that features a reduction in resistance when the exhaust gas temperature rises. Therefore, the sensor output voltage changes according to the exhaust gas temperature. When exhaust gas temperature rises, it lowers.
 
 
MONITOR EXECUTION
Continuous.
 
 
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)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • More than 2 seconds have passed since the power supply mode of the electric motor switch was ON.
  • 12V battery positive voltage is between 10.0 and 16.5 volts.
    or
  • More than 2 seconds have passed since the key-off evaporative leakage monitoring was started.
  • 12V battery positive voltage is between 10.0 and 16.5 volts.
Judgment Criterion
  • EGR gas temperature sensor output voltage is lower than 0.1 volt for 2 seconds [higher than 609°C (1,128°F)].
 
 
FAIL-SAFE AND BACKUP FUNCTION
None.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • EGR temperature sensor failed.
  • Short circuit 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), 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?
 
2.STEP 2. Check EGR temperature sensor itself.
Check EGR temperature sensor itself [Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Recirculation (EGR) System EXHAUST GAS RECIRCULATION (EGR) VALVE (STEPPER MOTOR) CHECK].
Q: Is the check result normal?
Replace the EGR temperature sensor [Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Exhaust Gas Recirculation (EGR) System EXHAUST GAS RECIRCULATION (EGR) VALVE REMOVAL AND INSTALLATION].
 
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?
 
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 950: EGR Gas Temperature
Q: Is the check result normal?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
 
6.STEP 6. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P040C-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
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).