P0449
DTC P0449
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0449
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Evaporative Emission (EVAP) Vent Solenoid Valve Control Circuit
Diagnostic Fault Information
Circuit/System Description
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.
Conditions for Running the DTC
* The ignition is ON.
* The system voltage is between 9-32 V.
* The DTC runs continuously when the above conditions are met.
Conditions for Setting the DTC
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.
Action Taken When the DTC Sets
DTC P0449 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0449 is a Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Description and Operation
Evaporative Emission Control System Description Description and Operation
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Electrical Information Reference
* Circuit Testing Circuit Testing
* Troubleshooting with a Test Lamp Troubleshooting with a Test Lamp
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
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. or operate the vehicle within the conditions from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the Q13 Evaporative Emission Vent Solenoid Valve.
2. Ignition ON, verify a test lamp illuminates between the Q13 Evaporative Emission Vent Solenoid Valve voltage supply circuit terminal 1 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 Q13 Evaporative Emission Vent Solenoid Valve.
3. Connect a test lamp between the voltage supply circuit terminal 1 and the control circuit terminal 2 at the Q13 Evaporative Emission Vent Solenoid Valve.
4. Command 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 Q13 Evaporative Emission Vent Solenoid Valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Control Module References for ECM replacement, programming, and setup