DTC Troubleshooting: P04F1
DTC P04F1: EVAP System Low Purge Flow Detected
Special Tools Required
?Vacuum Pump/Gauge, 0?30 inHg Snap-on YA4000A or equivalent, commercially available
?Vacuum/Pressure Gauge, 0?4 inHg 07JAZ-001000B
NOTE: Before you troubleshoot, review the general troubleshooting information.

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

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Select the EVAP TEST (ELCM) in the INSPECTION MENU, then select EVAP Leak Check Module Test with the HDS.

  

Is the result OK?

     
YES
     
     
     
If the test result is PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EVAP leak check module, the EVAP canister purge valve, and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
     
NO
     
     
     
The failure is duplicated. Go to step 2.
2.
EVAP canister purge line visual check:

EVAP canister purge line visual check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for poor connection, blockage, or damage at the EVAP canister purge line between the intake manifold 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 line, others):

Determine possible failure area (EVAP canister purge line, others)
?1.
Remove the EVAP canister purge valve with its connector and vacuum hose connected.

?2.
Disconnect the vacuum hose (purge line) (A) from the EVAP canister purge valve (B).


?3.
Disconnect the EVAP canister purge line (A) from the EVAP canister (B). Connect the T-fitting (C), the vacuum gauge, and the vacuum pump/gauge, 0?30 inHg to the EVAP canister purge line as shown.


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

Does the hose hold vacuum?

     
YES
     
     
     
Check for blockage in the EVAP purge line between the EVAP canister purge valve and the EVAP canister.?
     
NO
     
     
     
Go to step 4.
4.
EVAP canister purge valve check:

EVAP canister purge valve check
?1.
Inspect the EVAP canister purge valve.

Is the EVAP canister purge valve OK?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
5.
Purge tube A check:

Purge tube A check
?1.
Connect the vacuum pump/gauge, to purge tube A as shown.


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

Is there vacuum?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
Check for blockage at purge tube A between the intake manifold and the EVAP canister purge valve.?
6.
EVAP canister check:

EVAP canister check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the fuel vent tube (A) and the the EVAP canister drain hose (B) from the EVAP canister (C), and plug the EVAP canister port (D) and the EVAP leak check module port (E).


?3.
Disconnect the EVAP canister purge line (F) from the EVAP canister. Connect the vacuum pump/gauge.

?4.
Slowly apply the vacuum to the EVAP canister.

Does it hold vacuum?

     
YES
     
     
     
     
NO
     
     
     
The EVAP canister is OK. Go to step 7.
7.
EVAP leak check module performance check:

EVAP leak check module performance check
?1.
Connect the EVAP canister drain hose (A) to the EVAP canister (B).


?2.
Turn the vehicle to the ON mode.

?3.
Select the EVAP TEST (ELCM) in the INSPECTION MENU, then select CCV ON in the Single Solenoid Test with the HDS.

  

?4.
Check and record the Absolute Pressure of ELCM Pressure Sensor reading in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
Absolute Pressure of ELCM Pressure Sensor
    

?5.
Slowly apply about 1.3 kPa (0.4 inHg, 10 mmHg) of vacuum to the hose.
NOTE: Be careful not to exceed the vacuum. If you do, the EVAP leak check module can be damaged.

?6.
Check the Absolute Pressure of ELCM Pressure Sensor in the DATA LIST with the HDS.
Signal
Current conditions
Values
Unit
Absolute Pressure of ELCM Pressure Sensor
    

Does the value change?

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