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DTC P0451-00: Fuel Tank Gauge Pressure Sensor performance
 
 
 
 
CIRCUIT OPERATION
  • A power voltage of 5 volts is applied to the fuel tank differential pressure sensor connector terminal number 3 from the ECM connector terminal number 106.
  • The power voltage is grounded to the ECM connector terminal number 116 from the fuel tank differential pressure sensor connector terminal number 2.
  • The fuel tank differential pressure sensor connector terminal number 1 outputs a voltage signal to the ECM connector terminal number 96 according to the differential pressure between the internal pressure of the fuel tank and the atmospheric pressure.
 
 
TECHNICAL DESCRIPTION
  • The ECM monitors the fuel tank differential pressure sensor output voltage.
  • The ECM determines whether the fuel tank differential pressure sensor signal voltage is within normal operating parameters.
 
 
DESCRIPTIONS OF MONITOR METHODS
Detect malfunction if the fuel tank differential pressure sensor output value is out of specified range during refuel control mode or key-off evaporative leakage monitoring.
 
 
MONITOR EXECUTION
  • Once per refueling <Rationality – low>
  • Once per driving cycle <Rationality – high/low>
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC set in memory for the item monitored below) <Rationality – low>
  • Bypass valve monitor
  • Fuel tank solenoid valve monitor
  • Switching valve monitor
  • Fuel tank differential pressure sensor monitor
  • Evaporative emission purge system monitor
Sensor (The sensors below are determined to be normal) <Rationality – low>
  • Bypass valve
  • Fuel tank solenoid valve
  • Switching valve
  • Fuel tank differential pressure sensor
Other Monitor (There is no temporary DTC set in memory for the item monitored below) <Rationality – high/low>
  • 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 sensors below are determined to be normal) <Rationality – high/low>
  • Engine coolant temperature sensor
  • Intake air temperature sensor
 
 
DTC SET CONDITIONS <Rationality – low>
Logic Flow Chart
Check Conditions
  • More than 0.5 seconds have passed since the ECM is woken up.
  • 12V battery positive voltage is between 10.0 and 16.5 volts.
  • During the refuel control mode.
Judgment Criterion
  • When the fuel tank differential pressure outputs less than atmospheric pressure during decompression of fuel tank by pressing the fuel filler lid opener switch.
 
 
DTC SET CONDITIONS <Rationality – high/low>
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.
  • The fuel tank pressure at ECM wake-up is less than 20 kPa (5.9 in.Hg) or more than 40 kPa (11.8 in.Hg).
  • Accumulated time that power supply mode of electric motor switch is ON is more than 27 minutes.
Judgment Criteria
  • Barometric pressure measured by the fuel tank differential pressure sensor is out of specified range.
  • The fuel tank absolute pressure subtracted from the barometric pressure measured by the fuel tank pressure sensor is more than specified pressure.
  • The fuel tank pressure subtracted from the barometric pressure measured by the fuel tank differential pressure sensor is more than specified pressure.
  • The canister pressure is less than specified pressure.
 
 
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 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
  • Fuel tank differential pressure sensor failed.
  • Fuel tank pressure sensor failed.
  • Fuel tank differential pressure sensor 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. 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 P0451-00 is set.
Q: Is DTC other than P0451-00 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 840: Refuel System Differential Pressure Sensor
Q: Is the check result normal?
 
3.STEP 3. Check harness between fuel tank differential pressure sensor connector terminal number 1 and ECM connector terminal number 96, check harness between fuel tank differential pressure sensor connector terminal number 2 and ECM connector terminal number 116, and check harness between fuel tank differential pressure sensor connector terminal number 3 and ECM connector terminal number 106.
Check signal line for open/short circuit and damage.
Q: Are the check result normal?
Replace the fuel tank differential pressure sensor (Refer to ENGINE, Fuel Supply – Fuel Tank, Fuel Pump and Gauge Assembly FUEL PUMP MODULE DISASSEMBLY AND ASSEMBLY). Then
Repair or replace the connector, or repair the damaged harness wire.
 
4.STEP 4. 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 850: EVAP System Absolute Pressure Sensor
Q: Is the check result normal?
 
5.STEP 5. Check harness between fuel tank pressure sensor connector terminal number 1 and ECM connector terminal number 113, check harness between fuel tank pressure sensor connector terminal number 2 and ECM connector terminal number 112, and check harness between fuel tank pressure sensor connector terminal number 3 and ECM connector terminal number 114.
Check signal line for open/short circuit and damage.
Q: Are the check result normal?
Replace the fuel tank pressure sensor (Refer to ENGINE, Fuel Supply – Fuel Tank FUEL TANK DISASSEMBLY AND ASSEMBLY). Then
Repair or replace the connector, or repair the damaged harness wire.
 
6.STEP 6. Using scan tool (M.U.T.-III SE), check the data list after perform the evaporative emission system monitor test.
(1) Perform the evaporative emission system monitor test (Refer to EVAPORATIVE EMISSION CONTROL SYSTEM MONITOR TEST).
(2) Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 790: Tank differential pressure sensor shift NG
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).
 
7.STEP 7. Using scan tool (M.U.T.-III SE), check the data list after perform the evaporative emission system monitor test.
(1) Perform the evaporative emission system monitor test (Refer to EVAPORATIVE EMISSION CONTROL SYSTEM MONITOR TEST).
(2) Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 790: Tank differential pressure sensor shift NG
Q: Is the check result normal?
The inspection is complete.
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).