P0443

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 control module controls the EVAP canister purge solenoid valve ON time by grounding the control circuit via an internal switch called a driver.

P0449

Battery voltage is supplied to the EVAP canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver.

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match, for a minimum of 12 seconds.

DTCs P0443 and P0449 are Type B DTCs.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

P0443

With the ignition ON, and the 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 commanded state is increased, and decrease when the commanded state is decreased.

P0449

1. With the ignition ON and the engine OFF, command the EVAP vent solenoid 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.

P0443

1. Turn OFF the ignition.
2. Disconnect the EVAP canister purge solenoid valve.
3. Turn ON the ignition, with the 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 good ground.

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

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.

⇒	If the test lamp illuminates, test the control circuit of the EVAP canister purge solenoid valve for a short to ground.

6. Command the EVAP canister purge solenoid valve to 50 percent with a scan tool.

⇒	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 open or for a short to voltage.

⇒	If the circuits and the control module test normal, replace the EVAP canister purge solenoid valve.

P0449

1. Turn OFF the ignition.
2. Disconnect the EVAP canister vent solenoid valve.
3. Turn ON the ignition, with the engine OFF.
4. Probe the battery positive voltage circuit of the EVAP canister vent solenoid valve with a test lamp that is connected to a good ground.

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

5. Connect a test lamp between the control circuit of the EVAP vent solenoid valve and the battery positive voltage circuit of the EVAP canister vent solenoid valve at the EVAP vent valve harness connector.

⇒	If the test lamp illuminates, test the control circuit of the EVAP canister vent solenoid valve for a short to ground.

6. Command the EVAP canister vent solenoid ON and OFF.

⇒	If the test lamp does not illuminate with the commanded state of the valve, test the control circuit of the EVAP canister vent solenoid valve for a short to voltage or an open.

⇒	If the circuits and the control module test normal, replace the EVAP canister vent solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.