DTC P0443: EVAP Canister Purge Valve Circuit Malfunction

Special Tools Required

Vacuum Pump/Gauge, 0-30 In.Hg, 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 (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3, 000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
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.
Turn the ignition switch to LOCK (0), and allow the engine to cool to below 113°F (45°C).
Disconnect the vacuum hose (A) from the EVAP canister purge valve (B), and connect a vacuum pump/gauge, 0-30 in.Hg, to the hose.

Fig 1: Identifying Vacuum Hose And EVAP Canister Purge Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Start the engine, and let it idle.
Is there vacuum?

YES -Go to step 8.

NO -Go to Step 14.
Turn the ignition switch to LOCK (0).
Disconnect the EVAP canister purge valve 2P connector.
Check for continuity between EVAP canister purge valve 2P connector terminal No. 1 and body ground.

Fig 2: Checking Continuity Between EVAP Canister Purge Valve 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to Step 11.

NO -Go to step 23.
Jump the SCS line with the HDS.
Disconnect ECM/PCM connector B (44P).
Check for continuity between EVAP canister purge valve 2P connector terminal No. 1 and body ground.

Fig 3: Checking Continuity Between EVAP Canister Purge Valve 2P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the wire between the ECM/PCM (B3) and the EVAP canister purge valve, then go to step 24.

NO -Go to step 30.
Turn the ignition switch to LOCK (0).
Disconnect the EVAP canister purge valve 2P connector.
Turn the ignition switch to ON (II).
Measure the voltage between EVAP canister purge valve 2P connector terminal No. 2 and body ground.

Fig 4: Measuring Voltage Between EVAP Canister Purge Valve 2P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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. B12 IMA (10 A) fuse in the under-dash fuse/relay box, then go to step 24.
Turn the ignition switch to LOCK (0).
Jump the SCS line with the HDS.
Disconnect ECM/PCM connector B (44P).
Check for continuity between ECM/PCM connector terminal B3 and EVAP canister purge valve 2P connector terminal No. 1.

Fig 5: Checking Continuity Between ECM/PCM Connector Terminal B3 And EVAP Canister Purge Valve 2P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 22.

NO -Repair an open in the wire between the ECM/PCM (B3) and the EVAP canister purge valve, then go to step 24.
At the valve side, measure the resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.

Fig 6: Measuring Resistance Between EVAP Canister Purge Valve 2P Connector Terminals No. 1 And 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 23-26 Ω at room temperature (18-21°C, 65-70°F)?

YES -Go to step 30.

NO -Go to step 23.
Replace the EVAP canister purge valve (see EVAP CANISTER FILTER REPLACEMENT ).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the ECM/PCM with the HDS.
Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
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.
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 28, 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 ECM/PCM, then go to step 1. If the HDS indicates EXECUTING, or OUT OF CONDITION, keep idling until a result comes on.
Reconnect all connectors.
Update the ECM/PCM if it does not have the latest software (see ELD REPLACEMENT ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
Start the engine, and let it idle.
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 (see SUBSTITUTING THE ECM/PCM ), then go to step 32. If the ECM/PCM was substituted, go to step 1.

NO -Go to step 34.
Monitor the OBD STATUS for DTC P0443 in the DTCs MENU with the HDS.
Does the HDS Indicate PASSED?

YES -If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ). If any other Pending or Confirmed DTCs were indicated in step 33, 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 ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step 32. If the ECM/PCM was substituted, go to step 1. If the HDS indicates EXECUTING, or OUT OF CONDITION, keep idling until a result comes on.