DTC P0443: EVAP Canister Purge Valve Circuit Malfunction

Special Tools Required 

Vacuum pump/gauge; 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check for Temporary DTCs or 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 ECM/PCM.

5. Turn the ignition switch OFF, and allow the engine to cool below 140°F (60°C).
6. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) in the engine compartment, and connect a vacuum pump/gauge, 0-30 in.Hg, to the EVAP canister purge valve.
   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 OFF.
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  24.

11. Jump the SCS line with the HDS.
12. Disconnect ECM/PCM connector B (24P).
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 short in the wire between the EVAP canister purge valve and the ECM/PCM (B21), then go to step  25.

    NO  - Go to step  31.

14. Turn the ignition switch OFF.
15. Disconnect the EVAP canister purge valve 2P connector.
16. Turn the ignition switch ON (II).
17. Measure 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 open in the wire between the EVAP canister purge valve and the No. 3 IG METER (10 A) fuse in the under-dash fuse/relay box, then go to step  25.

18. Turn the ignition switch OFF.
19. Jump the SCS line with the HDS.
20. Disconnect ECM/PCM connector B (24P).
21. Connect EVAP canister purge valve 2P connector terminal No. 2 to body ground with a jumper wire.
    Fig 5: Connecting EVAP Canister Purge Valve 2P Connector Terminal No. 2 To Body Ground With Jumper Wire

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
22. Check for continuity between ECM/PCM connector terminal B21 and body ground.
    Fig 6: Checking Continuity Between ECM/PCM Connector Terminal B21 And Body Ground

    Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  23.

    NO  - Repair open in the wire between the EVAP canister purge valve and the ECM/PCM (B21), then go to step  25.

23. At the purge valve side, measure resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.
    Fig 7: 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 24.5 Ω at room temperature? 

    YES  - Go to step  31.

    NO  - Go to step  24.

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

    Is DTC P0443 indicated? 

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

    NO  - Go to step  30.

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

    Does the screen indicate PASSED? 

    YES  - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 29, go to the indicated DTC's troubleshooting.

    NO  - If the screen indicates FAILED, check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM, then go to step  1. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step  28.

31. Reconnect all connectors.
32. Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
33. Start the engine.
34. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P0443 indicated? 

    YES  - Check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  33. If the ECM/PCM was substituted, go to step  1.

    NO  - Go to step  35.

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

    Does the screen indicate PASSED? 

    YES  - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ). If any other Temporary DTCs or DTCs were indicated in step 34, go to the indicated DTC's troubleshooting.

    NO  - If the screen indicates FAILED, check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  33. If the ECM/PCM was substituted, go to step  1. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step  33.