DTC Troubleshooting: P04F0
DTC P04F0: EVAP System Incorrect 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
P04F0 EVAP System Incorrect 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 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 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.
Purge tube visual check 1:

Purge tube visual check 1
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for a poor connection, a blockage, or damage at purge tubes between the EVAP canister purge nozzle and the EVAP canister purge valve.

Are the tubes OK?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
Reconnect or repair the purge tube(s).?
3.
Purge tube visual check 2:

Purge tube visual check 2
?1.
Check for poor connection, blockage, or damage at the purge tube between the EVAP canister purge nozzle and the throttle body inlet pipe.

Is the tube OK?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
Reconnect or replace the purge tube.?
4.
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.
Slow apply about 2 kPa (0.6 inHg, 15 mmHg) of vacuum to the hose.

Does the hose hold vacuum?

     
YES
     
     
     
Check for a blockage in the EVAP canister purge line between the EVAP canister purge valve and the EVAP canister.?
     
NO
     
     
     
Go to step 5.
5.
Purge tube check 1:

Purge tube check 1
?1.
Disconnect the purge tube (A) from the throttle body inlet pipe (B), and connect the vacuum pump/gauge, 0?30 inHg, to the purge tube as shown.


?2.
Apply vacuum to the hose.

Does it hold vacuum?

     
YES
     
     
     
Check for blockage at the purge tube between the throttle body inlet pipe and the EVAP canister purge nozzle.?
     
NO
     
     
     
Go to step 6.
6.
Throttle body inlet pipe port check:

Throttle body inlet pipe port check
?1.
Check for debris or clogging at the port (A) of the throttle body inlet pipe (B).


Is the port OK?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Clean the Throttle body inlet pipe port, or replace the throttle body inlet pipe if needed.?
7.
Purge tube check 2:

Purge tube check 2
?1.
Disconnect the purge tube (A) from the EVAP canister purge nozzle (B), and connect the vacuum pump/gauge, 0?30 inHg, to the purge hose as shown.


?2.
Select the EVAP TEST in the INSPECTION MENU, and do the PCS (CPV) ON in the SINGLE SOLENOID with the HDS.

  

?3.
Apply vacuum to the tube.

Does it hold vacuum?

     
YES
     
     
     
Check for blockage at purge tubes between the EVAP canister purge nozzle and the EVAP canister purge valve.?
     
NO
     
     
     
Go to step 8.
8.
Non-return valve B check:

Non-return valve B check
?1.
Inspect non-return valve B.

Is the valve OK?

     
YES
     
     
     
Check for debris or clogging at the EVAP canister purge nozzle port and the throttle body inlet pipe port. If needed, replace the EVAP canister purge valve.?
     
NO