DTC Troubleshooting: P04F1
DTC P04F1: EVAP System Low Purge Flow Detected
Special Tools Required
?Vacuum Gauge 07YAJ-0010610
?Tube Joint Adapter 07410-5790503
?Fuel Pressure Gauge Attachment Set 07ZAJ-S5A0101
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P04F1 EVAP System Low Purge Flow Detected
      

1.
Problem verification:

Problem verification
?1.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Select the EVAP TEST in the INSPECTION MENU, then select the FUNCTION TEST with the HDS.

  

Is the result OK?

     
YES
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, the EVAP canister vent shut valve, and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
     
NO
     
     
     
Go to step 2.
2.
EVAP canister purge line visual check:

EVAP canister purge line visual check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Check for a poor connection, a blockage, or damage at the EVAP canister purge line between the throttle body and the EVAP canister.

Is the line OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Reconnect or repair the EVAP canister purge line.?
3.
Determine possible failure area (EVAP canister purge valve or purge line (EVAP canister side), others):

Determine possible failure area (EVAP canister purge valve or purge line (EVAP canister side), others)
?1.
Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) in the engine compartment.


?2.
Disconnect the vacuum hose (A) from the purge line (at the EVAP canister side), then connect a tube joint adapter, a vacuum gauge, and a vacuum pump/gauge to the hose as shown.
NOTE: Wrap the thread seal tape around the threads of the vacuum gauge, when connecting the vacuum gauge to the tube joint adapter.


?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.

?5.
Select EVAP TEST in the INSPECTION MENU, then select the EVAP PCS ON in the SINGLE SOLENOID with the HDS.

  

Is the vacuum release immediately?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Go to step 4.
4.
EVAP canister purge valve check:

EVAP canister purge valve check
?1.
Select EVAP TEST in the INSPECTION MENU, then select the EVAP PCS OFF in the SINGLE SOLENOID with the HDS.

  

?2.
Disconnect the vacuum hose (A) from the EVAP canister purge valve (B). Connect the vacuum gauge and the vacuum pump/gauge to the EVAP canister purge valve as shown.
NOTE: Wrap the thread seal tape around the threads of the vacuum gauge, when connecting the vacuum gauge to the tube joint adapter.


?3.
Apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.

?4.
Select the EVAP PCS ON in the SINGLE SOLENOID with the HDS.

  

Does the vacuum release immediately?

     
YES
     
     
     
The EVAP canister purge valve is OK. Check for a blockage in the purge line between the EVAP canister purge valve and the EVAP canister.?
     
NO
     
     
     
5.
EVAP canister purge line (engine side) check:

EVAP canister purge line (engine side) check
?1.
Connect the vacuum pump/gauge to the hose (A) as shown.


?2.
Start the engine, and let it idle.

Is there vacuum?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
Check for a blockage in the purge line between the EVAP canister purge valve and the throttle body.?
6.
FTP sensor performance check:

FTP sensor performance check
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Remove the FTP sensor with its connector connected.

?3.
Connect the vacuum gauge and the vacuum pump/gauge to the FTP sensor (A) as shown.
NOTE: Wrap the thread seal tape around the threads of the vacuum gauge, when connecting the vacuum gauge to the tube joint adapter.


?4.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?5.
Check and record the FTP sensor reading in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
FTP SENSOR
    

?6.
Slowly apply about 1.3 kPa (0.4 inHg, 10 mmHg) of vacuum to the hose.
Be careful not to exceed the vacuum. If you do, the FTP sensor can be damaged.

?7.
Check FTP SENSOR in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
FTP SENSOR
    

Does the value change?

     
YES
     
     
     
Check for a blockage at the EVAP canister purge line port.?
     
NO