P148D7E

DTC Code	DTC Name
P148D7E	Purge One Way Valve Stuck Open

DTC SUMMARY

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P148D7E	Purge One Way Valve Stuck Open	No. 1 check valve opened malfunction during key-off EVAP monitor	No. 1 check valve Leakage from EVAP line (No. 1 check valve - purge VSV)	Comes on	DTC stored	SAE: P148D

DTC No.	Monitoring Item	Detection Timing	Detection Logic	SAE
P148D7E	No. 1 check valve stuck open	While engine switch off	2 trip	P148D

DESCRIPTION

The description can be found in EVAP (Evaporative Emission) System.

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MONITOR DESCRIPTION

5 hours*1 after the engine switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

Tech Tips

*: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the engine switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the engine switch is turned off, the monitor check starts 2.5 hours later.

Sequence	Operation	Description	Duration
-	ECM activation	Activated by soak timer 5, 7 or 9.5 hours after engine switch turned off.	-
A	Atmospheric pressure measurement	Vent valve is turned off (vent) and EVAP system pressure is measured by ECM in order to register atmospheric pressure. If pressure in EVAP system is not between 70 kPa(abs) and 110 kPa(abs) [10.15 psi(abs) and 15.95 psi(abs)], ECM cancels EVAP system monitor.	60 seconds
B	First reference pressure measurement	In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally.	360 seconds
C	EVAP system pressure measurement	Vent valve is turned on (closed) to shut EVAP system. Negative pressure (vacuum) is created in EVAP system, and EVAP system pressure is then measured. Write down measured value as it will be used in leak check. If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.	15 minutes*
D	No. 1 Check Valve monitor	Purge VSV is opened and then EVAP system pressure is measured by ECM. If the pressure does not change, ECM interprets this as normal.	20 seconds
E	Vent Valve monitor	Vent valve is turned on (opened) and then EVAP system pressure is measured by ECM. Large increase indicates normal.	10 seconds
F	Second reference pressure measurement	After second reference pressure measurement, leak check is performed by comparing first and second reference pressure measurements. If stabilized system pressure is higher than second reference pressure, ECM determines that EVAP system is leaking.	60 seconds
-	Final check	Atmospheric pressure is measured and then monitoring result is recorded by ECM.	-

*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

*1	Purge VSV: Off (Closed)	*2	Purge VSV: On (Open)
*3	Vent Valve: Off (Vent)	*4	Vent Valve: On (Closed)
*5	Leak Detection Pump: Off	*6	Leak Detection Pump: On
*7	Reference Orifice (0.02 inch)	*8	Canister Pressure Sensor
*9	Canister	*10	Fuel Tank
*11	Canister Pump Module	*12	Canister Filter
*13	No. 1 Check Valve (Bank 1)	*14	No. 1 Check Valve (Bank 2)
*a	Operation A: Atmospheric Pressure Measurement	*b	Operation B, F: Reference Pressure Measurement
*c	Operation C: EVAP System Pressure Measurement	*d	Operation D: No. 1 Check Valve Monitor
*e	Operation E: Vent Valve Monitor	*f	Atmospheric Pressure
*g	Negative Pressure	-	-

P148D7E: No. 1 check valve stuck open

In operation D, the purge VSV opened and the EVAP system pressure is then measured by the ECM using the canister pressure sensor to conduct an EVAP leak check. If the pressure increases when the purge VSV is open, the ECM interprets this as the No. 1 check valve being stuck open. The ECM illuminates the MIL and stores the DTC.

MONITOR STRATEGY

Required Sensors/Components (Main)

No. 1 check valve

Purge VSV

Canister pump module

Frequency of Operation

Once per driving cycle

CONFIRMATION DRIVING PATTERN

Note

The Evaporative System Check (Automatic Mode) consists of 7 steps performed automatically by the GTS. It takes a maximum of approximately 24 minutes.
Do not perform the Evaporative System Check when the fuel tank is higher than 90% full because the cut-off valve may be closed, making the fuel tank leak check unavailable.
Do not run the engine during this operation.
When the temperature of the fuel is 35°C (95°F) or higher, a large amount of vapor forms and any check results become inaccurate. When performing the Evaporative System Check, keep the fuel temperature below 35°C (95°F).

Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Automatic Mode.
After the Evaporative System Check is completed, check for All Readiness by entering the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P148D7E.

Check the DTC judgment result.

GTS Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

Tech Tips

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.

PROCEDURE

GO TO EVAP SYSTEM

Refer to EVAP System.

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Result

Proceed to
NEXT

END

SFI SYSTEM(w/ Canister Pump Module), Diagnostic DTC:P148D7E