The evaporative emission (EVAP) canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. The EVAP canister purge valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP canister purge valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

The ECM detects the EVAP purge solenoid control circuit is open, shorted to ground, or shorted to voltage.

DTC P0443 is a Type B DTC.

DTC P0443 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Description and Operation

Evaporative Emission Control System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the EVAP Purge Solenoid ON and OFF with a scan tool. You should hear the solenoid click when commanded ON and OFF.

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit terminal A and ground.

⇒	If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.

3. Ignition OFF, connect a test lamp between the control circuit terminal B and the ignition 1 voltage terminal A.
4. Ignition ON, command the EVAP Purge Solenoid to 100 percent, and back to 0 percent with a scan tool. The test lamp should respond to the commanded state.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

5. If all circuits test normal, test or replace the EVAP purge solenoid.

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Test for 18-28 ohms of resistance between the control terminal B and the ignition 1 voltage terminal A.

⇒	If not within the specified range, replace the EVAP purge solenoid.

3. Test for infinite resistance between each terminal and the EVAP purge solenoid housing.

⇒	If not the specified value, replace the EVAP purge solenoid.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.