DTC Troubleshooting: P0443
DTC P0443: EVAP Canister Purge Valve Circuit Malfunction
Special Tools Required
Vacuum Pump/Gauge, 0?30 inHg Snap-on YA4000A or equivalent, commercially available
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0443 EVAP Canister Purge Valve Circuit Malfunction
      

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
Start the engine.

?4.
Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

?5.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0443 EVAP Canister Purge Valve Circuit Malfunction
      

Is DTC P0443 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EVAP canister purge 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.?
2.
Determine possible failure area (EVAP canister purge valve stuck open failure, EVAP canister purge valve stuck closed failure):

Determine possible failure area (EVAP canister purge valve stuck open failure, EVAP canister purge valve stuck closed failure)
?1.
Turn the vehicle to the OFF (LOCK) mode, and allow the engine to cool below 131 °F (55 °C).

?2.
Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) in the engine compartment, and connect a vacuum pump/gauge, 0?30 inHg, to the purge valve.


?3.
Start the engine, and let it idle.

Is there vacuum?

     
YES
     
     
     
The EVAP canister purge valve is stuck open. Go to step 3.
     
NO
     
     
     
The EVAP canister purge valve is stuck closed. Go to step 5.
3.
Determine possible failure area (PCS line, EVAP canister purge valve):

Determine possible failure area (PCS line, EVAP canister purge valve)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EVAP canister purge valve 2P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EVAP canister purge valve 2P connector: disconnected
Test point 1
EVAP canister purge valve 2P connector No. 1
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
4.
Shorted wire check (PCS line):

Shorted wire check (PCS line)
?1.
Jump the SCS line with the HDS, and wait more than 1 minute.


?2.
Disconnect the following connector.
PCM connector B (51P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EVAP canister purge valve 2P connector: disconnected
 
PCM connector B (51P): disconnected
Test point 1
EVAP canister purge valve 2P connector No. 1
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the PCS wire between the PCM (B15) and the EVAP canister purge valve.?
     
NO
     
     
     
The PCS wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0443 goes away and the PCM was updated, troubleshooting is complete. If DTC P0443 goes away and the PCM was substituted, replace the original PCM.?
5.
Open wire check (IG1 ACG/IG1(MAIN)/IG1(PCS) line):

Open wire check (IG1 ACG/IG1(MAIN)/IG1(PCS) line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
EVAP canister purge valve 2P connector

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
EVAP canister purge valve 2P connector: disconnected
Test point 1
EVAP canister purge valve 2P connector No. 2
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The IG1 ACG/IG1(MAIN)/IG1(PCS) wire is OK. Go to step 6.
     
NO
     
     
     
Repair an open in the IG1 ACG/IG1(MAIN)/IG1(PCS) wire between the EVAP canister purge valve and the No. B2 (10 A) fuse in the under-dash fuse/relay box.?
6.
Open wire check (PCS line):

Open wire check (PCS line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector B (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EVAP canister purge valve 2P connector: disconnected
 
PCM connector B (51P): disconnected
Test point 1
EVAP canister purge valve 2P connector No. 1
Test point 2
PCM connector B (51P) No. 15


Is there continuity?

     
YES
     
     
     
The PCS wire is OK. Go to step 7.
     
NO
     
     
     
Repair an open in the PCS wire between the PCM (B15) and the EVAP canister purge valve.?
7.
EVAP canister purge valve internal resistance check:

EVAP canister purge valve internal resistance check
?1.
At the purge valve side, measure the resistance between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
EVAP canister purge valve 2P connector: disconnected
 
PCM connector B (51P): disconnected
Test point 1
EVAP canister purge valve 2P connector No. 1 (EVAP canister purge valve side)
Test point 2
EVAP canister purge valve 2P connector No. 2 (EVAP canister purge valve side)


Is there about 22?27 ? at room temperature?

     
YES
     
     
     
The EVAP canister purge valve is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0443 goes away and the PCM was updated, troubleshooting is complete. If DTC P0443 goes away and the PCM was substituted, replace the original PCM.?
     
NO