DTC Troubleshooting
DTC Troubleshooting: P0443 (92)
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, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.
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 140 °F (60 °C).
6. Disconnect the vacuum hose (A) from the EVAP canister purge valve joint (B) in the engine compartment, then connect a vacuum pump/gauge, 0-30 inHg, to the vacuum hose.
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. 1 and body ground.
Is there continuity?
YES -
Go to step 11.
NO -
Go to step 24.
11. Jump the SCS line with the HDS.
12. Disconnect PCM connector C (49P).
13. Check for continuity between EVAP canister purge valve 2P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the EVAP canister purge valve and the PCM (C40), then go to step 25.
NO -
Go to step 31.
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. 2 and body ground.
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. 18 ACG (15 A) fuse in the driver's under-dash fuse/relay box, then go to step 25.
18. Turn the ignition switch to LOCK (0).
19. Jump the SCS line with the HDS.
20. Disconnect PCM connector C (49P).
21. Connect EVAP canister purge valve 2P connector terminal No. 1 to body ground with a jumper wire.
22. Check for continuity between PCM connector terminal C40 and body ground.
Is there continuity?
YES -
Go to step 23.
NO -
Repair an open in the wire between the EVAP canister purge valve and the PCM (C40), then go to step 25.
23. At the valve side, measure the resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.
Is there about 23-26 Ohms at room temperature?
YES -
Go to step 31.
NO -
Go to step 24.
24. Replace the EVAP canister purge valve Service and Repair.
25. Reconnect all connectors.
26. Turn the ignition switch to ON (II).
27. Reset the PCM with the HDS.
28. Do the PCM idle learn procedure PCM Idle Learn Procedure.
29. 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 30.
30. 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 29, 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.
31. Reconnect all connectors.
32. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.
33. Start the engine, and let it idle.
34. 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, then go to step 33. If the 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 HDS indicate PASSED?
YES -
If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 34, 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, then go to step 33. 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.