DTC P0443: EVAP Canister Purge Valve Circuit Malfunction

Special Tools Required 

Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available

1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
4. Check for Pending or Confirmed DTCs with the HDS.

   Is DTC P0443 indicated? 

   YES  -Go to step  5.

   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.

5. Turn the ignition switch to LOCK (0), and allow the engine to cool to below 113°F(45°C).
6. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B), and connect a vacuum pump/gauge, 0-30 inHg, to the hose.
   Fig 1: Identifying Vacuum Hose And EVAP Canister Purge Valve

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Start the engine, and let it idle.

   Is there vacuum? 

   YES  -Go to step 8.

   NO  -Go to step  14.

8. Turn the ignition switch to LOCK (0).
9. Disconnect the EVAP canister purge valve 2P connector.
10. Check for continuity between EVAP canister purge valve 2P connector terminal No. 2 and body ground.
    Fig 2: Checking Continuity Between EVAP Canister Purge Valve 2P Connector Terminal No. 2 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 11.

    NO  -Go to step  23.

11. Jump the SCS line with the HDS.
12. Disconnect PCM connector B (49P).
13. Check for continuity between EVAP canister purge valve 2P connector terminal No. 2 and body ground.
    Fig 3: Checking Continuity Between EVAP Canister Purge Valve 2P Connector Terminal No. 2 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short in the wire between the PCM (B3) and the EVAP canister purge valve, then go to step  24.

    NO  -Go to step  30.

14. Turn the ignition switch to LOCK (0).
15. Disconnect the EVAP canister purge valve 2P connector.
16. Turn the ignition switch to ON (II).
17. Measure the voltage between EVAP canister purge valve 2P connector terminal No. 1 and body ground.
    Fig 4: Measuring Voltage Between EVAP Canister Purge Valve 2P Connector Terminal No. 1 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 18.

    NO  -Repair an open in the wire between the EVAP canister purge valve and the No. 12 IMA (10 A) fuse in the under-dash fuse/relay box, then go to step  24.

18. Turn the ignition switch to LOCK (0).
19. Jump the SCS line with the HDS.
20. Disconnect PCM connector B (49P).
21. Check for continuity between PCM connector terminal B3 and EVAP canister purge valve 2P connector terminal No. 2.
    Fig 5: Checking Continuity Between PCM Connector Terminal B3 And EVAP Canister Purge Valve 2P Connector Terminal No. 2

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 22.

    NO  -Repair an open in the wire between the PCM (B3) and the EVAP canister purge valve, then go to step  24.

22. At the valve side, measure the resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.
    Fig 6: Measuring Resistance Between EVAP Canister Purge Valve 2P Connector Terminals No. 1 And No. 2

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 22-26 Ω at room temperature (65-70°F, 18-21°C)? 

    YES  -Go to step  30.

    NO  -Go to step 23.

23. Replace the EVAP canister purge valve (see EVAP CANISTER PURGE VALVE REPLACEMENT  ).
24. Reconnect all connectors.
25. Turn the ignition switch to ON (II).
26. Reset the PCM with the HDS.
27. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
28. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0443 indicated? 

    YES  -Check for poor connections or loose terminals at the EVAP canister purge valve and the PCM, then go to step  1.

    NO  -Go to step 29.

29. Monitor the OBD STATUS for DTC P0443 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step  28, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -If the HDS indicates FAILED, check for poor connections or loose terminals at the EVAP canister purge valve and the PCM, then go to step  1. If the HDS indicates EXECUTING, or OUT OF CONDITION, keep idling until a result comes on.

30. Reconnect all connectors.
31. Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
32. Start the engine, and let it idle.
33. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0443 indicated? 

    YES  -Check for poor connections or loose terminals at the EVAP canister purge valve and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step  32. If the PCM was substituted, go to step  1.

    NO  -Go to step 34.

34. Monitor the OBD STATUS for DTC P0443 in the DTCs MENU with the HDS.

    Does the HDS indicate PASSED? 

    YES  -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Pending or Confirmed DTCs were indicated in step  33, go to the indicated DTC'S TROUBLESHOOTING .

    NO  -If the HDS indicates FAILED, check for poor connections or loose terminals at the EVAP canister purge valve and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then go to step  32. If the PCM was substituted, go to step  1. If the HDS indicates EXECUTING, or OUT OF CONDITION, keep idling until a result comes on.