DTC Troubleshooting
DTC Troubleshooting: P0443, 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, 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 (A/T in P or N, M/T in neutral) 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 ECM/PCM.�
5. Turn the ignition switch to LOCK (0), and allow the engine to cool to below 131 °F (55 °C).
6. Disconnect the vacuum hose (A) from the purge valve (B) in the engine compartment, and connect a vacuum pump/gauge, 0-30 inHg, to the 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. 2 and body ground.
Is there continuity?
YES -
Go to step 11.
NO -
Go to step 23.
11. Jump the SCS line with the HDS.
12. Disconnect ECM/PCM connector B (49P).
13. Check for continuity between EVAP canister purge valve 2P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Repair short in the wire between the EVAP canister purge valve and the ECM/PCM (B3), 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.
Is there battery voltage?
YES -
Go to step 18.
NO -
Repair open in the wire between the EVAP canister purge valve and the No. 7 ACG (15 A) fuse in the driver's 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 ECM/PCM connector B (49P).
21. Check for continuity between ECM/PCM connector terminal B3 and EVAP canister purge valve 2P connector terminal No. 2.
Is there continuity?
YES -
Go to step 22.
NO -
Repair open in the wire between the EVAP canister purge valve and the ECM/PCM (B3), 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.
Is there about 23-26 Ohms at room temperature?
YES -
Go to step 30.
NO -
Go to step 23.
23. Replace the EVAP canister purge valve Service and Repair.
24. Reconnect all connectors.
25. Turn the ignition switch to ON (II).
26. Reset the ECM/PCM with the HDS.
27. Do the ECM/PCM idle learn procedure ECM/PCM Idle Learn Procedure (M/T).
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 ECM/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 screen 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 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 or OUT OF CONDITION, keep idling until a result comes on.
30. Reconnect all connectors.
31. Update the ECM/PCM if it does not have the latest software ECM/PCM Update (M/T), or substitute a known-good ECM/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 ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM, then go to step 32. If the ECM/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 screen indicate PASSED?
YES -
If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair. If any other Pending or Confirmed DTCs were indicated in step 33, 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, then go to step 32. If the ECM/PCM was substituted, go to step 1. If the screen indicates EXECUTING or OUT OF CONDITION, keep idling until a result comes on.