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DTC P0450: Evaporative Emission System Pressure Sensor Malfunction
 
 
 
 
CIRCUIT OPERATION
  • The ECM terminal FDP5 supplies a 5 volts reference signal to the fuel tank differential pressure sensor. The fuel tank differential pressure sensor is grounded through the ECM terminal FDPE.
  • The fuel tank differential pressure sensor returns a voltage signal to the ECM terminal FDPS that is proportional to the pressure in the fuel tank.
 
 
TECHNICAL DESCRIPTION
  • The ECM monitors the fuel tank differential pressure sensor signal voltage.
  • The ECM determines whether the fuel tank differential pressure sensor signal voltage is within normal operating parameters.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • Fuel tank differential pressure sensor output does not change when fuel tank pressure sensor output has changed.
 
 
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)
  • Fuel tank pressure sensor monitor
  • Fuel tank differential pressure sensor monitor
  • Fuel tank vapor line monitor
  • Vehicle speed sensor monitor
Sensor (The sensors below are determined to be normal)
  • Fuel level sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • When the amount of change of the fuel tank pressure sensor output signal is 1 kPa (0.3 in.Hg) or more.
  • Power supply mode of electric motor switch is ON.
  • 12V starter battery positive voltage is between 10 and 16.5 volts.
  • Fuel level is 70% or less.
  • The fuel tank differential pressure sensor output signal is more than -5.6 kPa (-1.65 in.Hg) and is less than +5.6 kPa (+1.65 in.Hg).
  • During stopping the vehicle.
  • It is not refuel control mode.
Judgment Criteria
  • The change of fuel tank differential pressure sensor output signal is less than specified value for 3 times.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Fuel filler lid cannot be opened even when pressing the fuel filler lid opener switch.
  • 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 .
 
 
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
  • Fuel tank differential pressure sensor failed.
  • Fuel tank differential pressure sensor circuit harness damage, or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), check data list item 210: Fuel Tank Differential Pressure Sensor.
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Disconnect the hose D from the bypass valve.
(3) Plug the disconnected end of hose D.
(4) Turn on the power supply mode of the electric motor switch.
(5) Remove the fuel cap.
(6) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 210, Fuel Tank Differential Pressure Sensor.
  • The standard value should be -0.57 to 0.57 kPa (-0.168 to 0.168 in.Hg).
(7) Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube by using fuel tank adapter (MLR-8382) and pressurize the fuel tank in the range of 30 kPa (8.9 in. Hg) or less.
  • The fuel tank pressure reading should increase.
(8) Turn off the power supply mode of the electric motor switch.
(9) Remove the evaporative emission system pressure pump (Miller number 6872A) and the fuel tank adapter (MLR-8382), and reinstall the fuel cap.
(10) Connect hose D to the bypass valve.
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 continuity at fuel tank differential pressure sensor connector.
(1) Disconnect the fuel tank differential pressure sensor connector and measure at the harness side.
(2) Check for the continuity between terminal FDPE and ground.
  • Continuity (2 ohms or less).
Does continuity exist?
Go to Step 5.
Go to Step 3.
 
STEP 3. Check of open circuit and harness damage in FDPE line between fuel tank differential pressure sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 7.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check data list item 210: Fuel Tank Differential Pressure Sensor.
(1) Disconnect the hose D from the bypass valve.
(2) Plug the disconnected end of hose D.
(3) Turn on the power supply mode of the electric motor switch.
(4) Remove the fuel cap.
(5) Set scan tool (M.U.T.-IIISE) to the data reading mode for item 210, Fuel Tank Differential Pressure Sensor.
  • The standard value should be -0.57 to 0.57 kPa (-0.168 to 0.168 in.Hg).
(6) Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube by using fuel tank adapter (MLR-8382) and pressurize the fuel tank in the range of 30 kPa (8.9 in. Hg) or less.
  • The fuel tank pressure reading should increase.
(7) Turn off the power supply mode of the electric motor switch.
(8) Remove the evaporative emission system pressure pump (Miller number 6872A) and the fuel tank adapter (MLR-8382), and reinstall the fuel cap.
(9) Connect hose D to the bypass valve.
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 7.
 
STEP 5. Check of harness damage in FDP5 and FDPS line between fuel tank differential pressure sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 6.
Repair the connector(s) or wiring harness. Then go to Step 7.
 
STEP 6. Replace the fuel tank differential pressure sensor.
(1) Replace the fuel tank differential pressure sensor.
(2) Carry out test drive with the drive cycle pattern. Refer to Diagnostic Function. OBD-II Drive Cycle - Pattern 4 .
(3) Check the diagnostic trouble code (DTC).
Is DTC P0450 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 7.
The inspection is complete.
 
STEP 7. Perform 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 P0450 set?
Retry the troubleshooting.
The inspection is complete.