DTC Troubleshooting: P0443 (92)

DTC P0443:  Evap Canister Purge Valve Circuit Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

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 (min-1) 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 5.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM.n


5.Turn the ignition switch OFF, and allow the engine to cool below 60 °C (140 °F).

6.Disconnect the vacuum hose (A) from the purge valve (B) in the engine compartment, and connect a vacuum pump/gauge to the hose.

 

7.Start the engine, and let it idle.

Is there vacuum?


YES - Go to 8.


NO - Go to 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.

 

Is there continuity?


YES - Go to 11.


NO - Go to 23.

11.Jump the SCS line with the HDS.

12.Disconnect ECM/PCM connector B (44P).

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 24.


NO - Go to 30.


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.

 

Is there battery voltage?


YES - Go to 18.


NO - Repair open in the wire between the EVAP canister purge valve and the No. 3 ALTERNATOR (10 A) fuse in the under-dash fuse/relay box, then go to 24.


18.Turn the ignition switch OFF.

19.Jump the SCS line with the HDS.

20.Disconnect ECM/PCM connector B (44P).

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 22.


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

22.Measure resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.

 

Is there about 33 W at room temperature?


YES - Go to 30.


NO - Go to 23.


23.Replace the EVAP canister purge valve.

24.Reconnect all connectors.

25.Turn the ignition switch ON (II).

26.Reset the ECM/PCM with the HDS.

27.Do the ECM/PCM idle learn procedure.

28.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0443 is indicated, check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Go to 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.n


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 1. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to 27 and recheck.


30.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

31.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0443 is indicated, check for poor connections or loose terminals at the EVAP canister purge valve and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n