DTC Troubleshooting: P0443 (92-4)

DTC P0443 (92-4):  EVAP Canister Purge Valve Malfunction

1.Reset the ECM/PCM.

2.Start the engine. Hold the engine at 3,000 rpm (min-1) without load (in Park or neutral) until the radiator fan comes on.

Is the DTC P0443 indicated?


YES - Go to 3.


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


3.Turn the ignition switch OFF.

4.Disconnect the vacuum hose (A) from the EVAP canister purge valve (B) and connect a vacuum gauge (C) to the hose.

 

5.Start the engine end let it idle.

Is there vacuum?


YES - Go to 6.


NO - Go to 11.


6.Turn the ignition switch OFF.

7.Disconnect the EVAP canister purge valve 2P connector.

8.Check for continuity between the EVAP canister purge valve 2P connector terminal No. 2 and body ground.

 

Is there continuity?


YES - Go to 9.


NO - Replace the EVAP canister purge valve.n


9.Disconnect ECM/PCM connector B (24P).

10.Check for continuity between the 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 (B21).n


NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n

11.Turn the ignition switch OFF.

12.Disconnect the EVAP canister purge valve 2P connector.

13.Turn the ignition switch ON (II).

14.At the harness side, measure voltage between the EVAP canister purge valve 2P connector terminal No. 1 and body ground.

 

Is there battery voltage?


YES - Go to 15.


NO - Repair open in the wire between No. 3 (7.5A) fuse in the under-dash fuse/relay box and the EVAP canister purge valve.n


15.Turn the ignition switch OFF.

16.Reconnect the EVAP canister purge valve 2P connector.

17.Turn the ignition switch ON (II).

18.Measure voltage between ECM/PCM connector terminals A5 and B21.

 

Is there battery voltage?


YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original  ECM/ PCM.n


NO - Repair open in the wire between the EVAP canister purge valve and the ECM/PCM (B21). If wire is OK, replace the EVAP canister purge valve.n