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DTC P043E: Reference Orifice Low Flow
 
 
 
 
TECHNICAL DESCRIPTION
The reference pressure is measured 3 times at most during the key-off evaporative leakage monitoring. When the measured reference pressure deviates from the normal range, it is judged that the reference orifice is blocked.
 
 
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 starter battery positive voltage is 11 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 % 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).
Judgment Criteria
  • The first reference pressure subtracted from the barometric pressure is more than 3.94 - 4.30 kPa (1.164 - 1.270 in.Hg) for 10 seconds.
  • The second reference pressure subtracted from the barometric pressure is more than 4.74 - 5.10 kPa (1.400 - 1.506 in.Hg) for 10 seconds.
  • The third reference pressure subtracted from the barometric pressure is more than 4.74 - 5.10 kPa (1.400 - 1.506 in.Hg) for 10 seconds.
noteThe threshold value varies depending on the canister pressure.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle Pattern 4 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Excessive negative pressure of the evaporative emission leak detection pump
  • Reference orifice blockage
  • Shorted evaporative emission leak detection pump circuit, harness damage or connector damage.
  • ECM failed.
 
 
 
DIAGNOSIS
STEP 1. Check of short to power supply in EVB line between evaporative leak check module connector and ECM connector.
Is the harness wire in good condition?
Go to Step 2.
Repair the connector(s) or wiring harness. Then go to Step 3.
 
STEP 2. Replace the reference orifice (integrated in evaporative emission canister).
(1) Replace the reference orifice (integrated in evaporative emission canister).
(2) Carry out an evaporative emission system monitor. Refer to Evaporative Emission System Monitor Test .
(3) Check the item 186, Reference Orifice Low Flow in the data list.
(4) Turn off the power supply mode of the electric motor switch.
Is the data list "Normal"?
The inspection is complete.
Replace the ECM (Refer to Removal and Installation ). Then go to Step 3.
 
STEP 3. 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 4 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P043E set?
Retry the troubleshooting.
The inspection is complete.