Cruze

DTC P0443 or P0449

An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge solenoid valve. The engine control module (ECM) grounds the evaporative emission canister purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The evaporative emission canister purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage.

Battery voltage is supplied to the evaporative emission canister solenoid valve. The ECM grounds the evaporative emission canister vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the evaporative emission canister vent solenoid valve as ON or OFF.

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 and P0449 are Type B DTCs.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Description and Operation

Evaporative Emission Control System Description

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

P0443

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

P0449

1. Ignition ON, engine OFF, command the evaporative emission vent solenoid valve ON and OFF with a scan tool.
2. Listen for a click when the valve operates. Verify that both the ON, and the OFF states are commanded.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve or the Q13 Evaporative Emission Vent Solenoid Valve.
2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal 2 and ground.

⇒	If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the evaporative emission canister purge solenoid valve.

3. Connect a test lamp between the voltage supply circuit terminal 2 and the control circuit terminal 1.
4. Command the EVAP canister purge solenoid valve to 50% with a scan tool, or the EVAP canister vent solenoid valve ON and OFF. The test lamp should respond to the command.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	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 K20 Engine Control Module.

5. If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.