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DTC P1401-09: Evaporative leak check pump performance
 
 
 
 
TECHNICAL DESCRIPTION
  • Evaporative emission leak detection pump is built into the Evaporative Leak Check Module (ELCM).
  • During the key-off evaporative leakage monitoring, when pulsation is observed in evaporative emission canister pressure while the evaporative emission leak detection pump is operating, it is judged as an evaporative emission leak detection pump pulsation failure.
 
 
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)
  • Evaporative emission purge solenoid monitor
  • Bypass valve monitor
  • Fuel tank solenoid valve monitor
  • Switching valve monitor
  • Canister pressure sensor monitor
  • Manifold absolute pressure sensor monitor
  • Fuel tank pressure sensor monitor
  • Fuel tank differential pressure sensor monitor
  • Barometric pressure sensor/manifold absolute pressure correlation
  • Barometric pressure sensor monitor
  • Fuel level sensor monitor
  • Engine off timer monitor
  • Controller area network (CAN) monitor
Sensor (The sensor below is determined to be normal)
  • Engine coolant temperature sensor
  • Intake air temperature sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • Power supply mode of electric motor switch is OFF.
  • 12V battery positive voltage is 11.0 volts or higher.
  • Engine coolant temperature is higher than 4°C (39°F) and lower than 35°C (95°F).
  • Intake air temperature at ECM wake-up is higher than 4°C (39°F) and lower than 35°C (95°F).
  • ECM is woken up in 5, 6 or 8.5 hours since the power supply mode of electric motor switch was OFF.
  • Barometric pressure is 76 kPa (22.4 in.Hg) or higher.
  • Fuel level is 85 percent or less.
  • Fuel tank pressure at ECM wake-up is less than 19.96 kPa (5.89 in.Hg) or more than 40.00 kPa (11.81 in.Hg).
  • Accumulated time that electric motor switch is ON is more than 1,620 seconds.
Judgment Criteria
  • The minimum canister pressure subtracted from maximum canister pressure is more than 0.358 kPa (0.1057 in.Hg).
  • The ECM monitors for this condition for 3 cycles of 9 seconds each during drive cycles.
 
 
FAIL-SAFE AND BACKUP FUNCTION
Indicates "REFUELING SYSTEM SERVICE REQUIRED" on the information screen in the multi-information display.
 
 
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:)
  • Evaporative emission leak detection pump (built into the ELCM) failed (pulsation).
  • Evaporative emission leak detection pump circuit harness damage 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
1.STEP 1. Check harness between ELCM connector terminal number 2 and ECM connector terminal number 93.
Check output line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
2.STEP 2. Check harness between ECM connector terminal number 1 and ground.
Check ground line for damage.
Q: Is the check result normal?
Repair or replace the connector, or repair the damaged harness wire.
 
3.STEP 3. Using scan tool (M.U.T.-III SE) to check the data list after replace ELCM and perform the evaporative emission system monitor test.
(1) Replace the ELCM (Refer to ENGINE, Engine, Motor and Emission Control – Emission Control – Evaporative Emission System EVAPORATIVE EMISSION CANISTER REMOVAL AND INSTALLATION).
(2) Perform the evaporative emission system monitor test (Refer to EVAPORATIVE EMISSION CONTROL SYSTEM MONITOR TEST).
(3) Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 460: Pump pulsation NG
Q: Is the check result normal?
The inspection is complete.
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).