Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge solenoid valve. The EVAP canister purge solenoid valve is pulse width modulated (PWM). The scan tool displays the amount of ON time as a percentage. The control module monitors the status of the driver. The engine control module (ECM) controls the EVAP canister purge solenoid valve ON time by grounding the control circuit via an internal switch called a driver. If the ECM detects an incorrect voltage for the commanded state of the driver this DTC sets.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 6 seconds.

DTC P0443 is a type B DTC.

DTC P0443 is a type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Scan Tool Reference

Control Module References

Ignition ON , engine OFF, you should hear a clicking sound when the EVAP canister purge solenoid valve is commanded to 50 percent with a scan tool. The clicking sound should stop when the EVAP canister purge solenoid valve is commanded to 0 percent. The rate at which the valve cycles should increase when the command state is increased and decrease when the command state is decreased.

1. Ignition OFF.
2. Disconnect the EVAP canister purge solenoid valve.
3. Ignition ON, engine OFF.
4. Probe the ignition 1 voltage circuit of the EVAP canister purge solenoid valve with a test lamp that is connected to a known ground.

⇒	If the test lamp does not illuminate, test the circuit for an short to ground or an open/high resistance.

5. Connect a test lamp between the control circuit of the EVAP canister purge solenoid valve and the ignition 1 voltage circuit of the EVAP canister purge solenoid valve. The test lamp should not illuminate.

⇒	If the test lamp illuminates, test the control circuit of the EVAP canister purge solenoid valve for a short to ground or an open/high resistance. If all circuits test normal replace the ECM.

6. Command the EVAP canister purge solenoid valve to 50 percent with a scan tool. The test lamp should flash or illuminate with the command.

⇒	If the test lamp does not flash or illuminate with the command, test the control circuit of the EVAP canister purge solenoid valve for an short to ground or an open/high resistance. If the circuit tests normal, replace the engine ECM.

7. If the circuits and the ECM test normal, replace the EVAP canister purge solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.