DTC P0451:00 [PCM (SKYACTIV-G 2.5T)]

id0102s8300700

Note
•  To determine the malfunctioning part, proceed with the diagnostics from "Function Inspection Using M-MDS".

Details On DTCs

DESCRIPTION

Fuel tank pressure sensor: sensor characteristic malfunction
DETECTION CONDITION
Determination conditions
•  The fuel tank pressure sensor input voltage is the threshold or more.
Preconditions
•  Battery voltage: above 8 V*1
•  Period ignition is switched off before engine starts: 120 min or more
•  Purge solenoid valve not operating
•  The following DTCs are not detected:
?  Purge solenoid valve: P0443:00
?  Evaporative passage blockage: P0496:00, P1450:00
*1: Standard can be verified by displaying PIDs using M-MDS
Malfunction determination period
•  During one drive cycle
Drive cycle
•  2
Self test type
•  CMDTC self test
Sensor used
•  Fuel tank pressure sensor
FAIL-SAFE FUNCTION
•  Not applicable
VEHICLE STATUS WHEN DTCs ARE OUTPUT
•  Illuminates check engine light.
POSSIBLE CAUSE
•  Fuel tank pressure sensor connector or terminals malfunction
•  PCM connector or terminals malfunction
•  Fuel tank pressure sensor malfunction
•  Charcoal canister malfunction
•  CV solenoid valve malfunction
•  Evaporative hose malfunction
•  PCM malfunction

System Wiring Diagram

•  Not applicable

Function Explanation (DTC Detection Outline)

•  The PCM detects the pressure of the fuel tank based on the fuel tank pressure sensor signal. The PCM determines a fuel tank pressure sensor signal error based on the condition in which the fuel tank pressure sensor voltage continues to be the specified value or more, and stores a DTC.
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Repeatability Verification Procedure

1.  Switch the ignition off.
2.  Leave the vehicle for 2 hours or more.
3.  Start the engine and leave it idling for 1 min.

PID Item/Simulation Item Used In Diagnosis

PID/DATA monitor item table

Item

Definition

Unit

Condition/Specification
AAT
Ambient air temperature
°C, °F
•  Displays ambient air temperature
FTP
Fuel tank pressure
Pa {KPa}, mBar {Bar}, psi, in H20
•  Displays fuel tank pressure
Fuel tank pressure sensor voltage
V
•  Fuel tank pressure is equal to barometric pressure: Approx. 2.6 V


Function Inspection Using M-MDS

STEP

INSPECTION

RESULTS

ACTION
1
PURPOSE: VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
PURPOSE: RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
Note
•  Recording can be facilitated using the screen capture function of the PC.
•  Record the FREEZE FRAME DATA/snapshot data on the repair order.
—
Go to the next step.
3
PURPOSE: VERIFY IF FUEL TANK PRESSURE SENSOR HAS MALFUNCTION
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Is the PENDING CODE/DTC P0452:00, P0453:00 or P0454:00 also present?
Yes
The possibility of a fuel tank pressure sensor malfunction is high.
•  Go to the applicable PENDING CODE or DTC inspection.
No
Go to the next step.
4
PURPOSE: INSPECTION OF CLOGGING BETWEEN FUEL TANK PRESSURE SENSOR AND FUEL TANK
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Is the PENDING CODE/DTC P00FE:00 or P144A:00 also present?
Yes
The possibility of clogging between fuel tank pressure sensor and fuel tank is high.
•  Go to the applicable PENDING CODE or DTC inspection.
No
Go to the next step.
5
PURPOSE: VERIFY IF CV SOLENOID VALVE HAS MALFUNCTION
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Is the PENDING CODE/DTC P0446:00 also present?
Yes
The possibility of a CV solenoid valve malfunction is high.
•  Go to the applicable PENDING CODE or DTC inspection.
No
Go to the next step.
6
PURPOSE: VERIFY IF FUEL TANK PRESSURE IS STUCK TO EITHER LOW OR HIGH PRESSURE SIDE
•  Start the engine and idle it.
•  Access the FTP PID using the M-MDS.
•  Is the FTP PID value 0.424 kPa {0.00432 kgf/cm2, 0.0615 psi} or more?
Yes
The possibility that the fuel tank pressure is stuck to the high pressure side is high.
•  Go to the next step.
No
The possibility that the fuel tank pressure is stuck to the low pressure side is high.
•  Go to the troubleshooting procedure to perform the procedure from Step 3.
7
PURPOSE: VERIFY IF MALFUNCTION CAUSE IS FREEZING OF FUEL TANK PRESSURE SENSOR BY VERIFYING AMBIENT TEMPERATURE
•  Start the engine and idle it.
•  Access the AAT PID using the M-MDS.
•  Is the AAT PID value 0 °C {32 °F} or less?
Yes
The possibility of a malfunction caused by freezing of the fuel tank pressure sensor is high.
•  Go to the troubleshooting procedure to perform the procedure from Step 1.
No
Go to the troubleshooting procedure to perform the procedure from Step 2.

Troubleshooting Diagnostic Procedure

Intention of troubleshooting procedure
•  Step 1
?  Visually verify that there are no traces of freezing on the fuel tank pressure sensor.
•  Step 2
?  Inspect the charcoal canister for clogging.
•  Step 3
?  Perform a unit inspection of the CV solenoid valve.
•  Step 4
?  Verify that there is no breakage or clogging in the evaporative hose.
•  Step 5
?  Perform a unit inspection of the fuel tank pressure sensor.
•  Step 6—7
?  Verify that the primary malfunction is resolved and there are no other malfunctions.

STEP

INSPECTION

RESULTS

ACTION
1
PURPOSE: VISUALLY VERIFY THAT THERE ARE NO TRACES OF FREEZING ON THE FUEL TANK PRESSURE SENSOR
•  Visually inspect for fuel tank pressure sensor.
•  Can traces of freezing be verified on the fuel tank pressure sensor?
Yes
Evaporative gas freezes when the ambient temperature is low, and it is highly possible that the fuel tank pressure sensor measurement is affected because the vehicle was not refueled appropriately.
•  Replace the fuel, then go to Step 6.
No
Go to Step 5.
2
PURPOSE: INSPECTION OF CHARCOAL CANISTER FOR CLOGGING
•  Inspect for clogging in the charcoal canister.
•  Is there any malfunction?
Yes
Replace the charcoal canister, then go to Step 6.
(See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
3
PURPOSE: DETERMINE INTEGRITY OF CV SOLENOID VALVE
•  Inspect the CV solenoid valve.
•  Is there any malfunction?
Yes
Replace the CV solenoid valve, then go to Step 6.
(See CANISTER VENT (CV) SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
4
PURPOSE: INSPECTION OF EVAPORATIVE HOSE FOR BREAKAGE OR CLOGGING
•  Inspect for breakage or clogging in the evaporative hose (hose between CV solenoid valve and atmosphere).
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results, then go to Step 6.
No
Go to the next step.
5
PURPOSE: DETERMINE INTEGRITY OF FUEL TANK PRESSURE SENSOR
•  Inspect the fuel tank pressure sensor.
•  Is there any malfunction?
Yes
Replace the charcoal canister, then go to the next step.
(See CHARCOAL CANISTER REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
No
Go to the next step.
6
PURPOSE: VERIFICATION OF VEHICLE REPAIR COMPLETION
•  Reconnect all the removed parts.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Implement the repeatability verification procedure.
•  Perform the Pending Trouble Code Access Procedure.
•  Is the PENDING CODE for this DTC present?
Yes
Repeat the inspection from Step 1 of the troubleshooting diagnostic procedure.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
7
PURPOSE: VERIFY IF THERE IS ANY OTHER MALFUNCTION
•  Is any other DTC or pending code stored?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
DTC troubleshooting completed.