Volt

DTC P0443, P0458, or P0459

The evaporative emission (EVAP) purge solenoid valve is used to purge fuel vapor from the EVAP canister to the inlet manifold. The EVAP purge solenoid valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP purge solenoid 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 that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 5 s.

DTCs P0443, P0458 and P0459 are Type B DTCs.

DTCs P0443, P0458 and P0459 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Evaporative Emission Control System Description

Hybrid Modes of Operation Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Vehicle in Service Mode, command the EVAP purge solenoid valve to 50 percent with a scan tool. You should hear the solenoid clicking.
2. Engine running, command the EVAP purge solenoid valve from 0 to 50 percent and back to 0 percent with a scan tool while observing the control circuit status parameters listed below:

•	EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status

•	EVAP Purge Solenoid Valve Control Circuit Open Test Status

•	EVAP Purge Solenoid Valve Control Circuit Low Voltage Test Status

Each parameter should display OK or Not Run.

3. 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.

1. Vehicle OFF, disconnect the harness connector at the Q12 evaporative emission purge solenoid valve.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.

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

3. Test for 2.5-3.5 V between the control circuit terminal 2 and ground

⇒	If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the K20 engine control module.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

4. Command the EVAP purge solenoid valve from 0 to 100 percent with a scan tool. The DMM should transition from 2.5-3.5 V at 0 percent, to less than 0.2 V when commanded to 100 percent.

⇒	If the circuit voltage does not correspond to the specified values, replace the K20 engine control module

5. If all circuits test normal, test or replace the Q12 evaporative emission purge solenoid valve

1. Vehicle OFF, disconnect the harness connector at the Q12 evaporative emission purge solenoid valve

2. Test for 25.0-30.0 Ω between the control terminal 2 and the ignition voltage terminal 1.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.