DTC Troubleshooting: P0443 (92-4)

DTC P0443 (92-4):  A electrical problem in the EVAP Canister Purge Valve circuit

1.Reset the ECM/PCM.

2.Turn the ignition switch ON (II).

Is the DTC P0443 indicated?


YES - Go to 3.


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


3.Turn the ignition switch OFF.

4.Disconnect the vacuum hose (A) from the EVAP canister (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 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 the negative cable from the battery.

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

11.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 (B21).n


NO - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original  ECM/ PCM.n

12.Turn the ignition switch OFF.

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

14.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Go to 16.


NO - Repair open in the wire between No. 4 ACG (10 A) fuse in the under-dash fuse/relay box and the EVAP canister purge valve.n


16.Turn the ignition switch OFF.

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

18.Turn the ignition switch ON (II).

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

 

Is there battery voltage?


YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, 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