Diagnostic Instructions

DTC Descriptors

DTC P0443 : Evaporative Emission (EVAP) Purge Solenoid Control Circuit

DTC P0458: Evaporative Emission (EVAP) Purge Solenoid Control Circuit Low Voltage

DTC P0459: Evaporative Emission (EVAP) Purge Solenoid Control Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition 1 Voltage	P0458	P0443	--	--
EVAP Canister Purge Valve Control Circuit	P0458	P0443	P0459	--

Circuit/System Description

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. If the ECM detects the control circuit voltage is within a predetermined range when the circuit is commanded OFF, this DTC sets.

Conditions for Running the DTC

Conditions for Setting the DTC

P0443

The ECM detects the voltage on the EVAP canister purge valve control is between 4-98 percent when the driver is commanded OFF for greater than 5 seconds.

P0458

The ECM detects the EVAP purge solenoid control circuit is open for greater than 5 seconds.

P0459

The ECM detects the EVAP purge solenoid control circuit is shorted to ground or voltage for greater than 5 seconds.

Action Taken When the DTC Sets

DTCs P0443, P0458 and P0459 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0443, P0458 and P0459 are Type A DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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

Circuit/System Verification

1. Ignition ON, command the EVAP purge solenoid ON with a scan tool. You should hear and feel an audible click for about 3-5 seconds.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Ignition ON, test for B+ between the ignition 1 voltage circuit terminal 2 and ground.

⇒	If less than the specified range, test the ignition 1 voltage circuit for a short to ground or an open/high resistance.

3. Connect a test lamp between the control circuit terminal 1 and the ignition 1 voltage circuit terminal 2.
4. Command the EVAP purge solenoid ON with a scan tool. The test lamp should turn ON and OFF for about 3-5 seconds.

⇒	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.

Component Testing

1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Test for 24-28 ohms of resistance between the control terminal 1 and the ignition 1 voltage terminal 2.

⇒	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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.