P0498

DTC P0449, P0498, or P0499

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
- Evaporative Emission (EVAP) Vent Solenoid Valve Control Circuit

DTC P0498
- Evaporative Emission (EVAP) Vent Solenoid Valve Control Circuit Low Voltage

DTC P0499
- Evaporative Emission (EVAP) Vent Solenoid Valve Control Circuit High Voltage

Diagnostic Fault Information






Circuit/System Description

Battery voltage is supplied to the normally closed evaporative emission (EVAP) vent solenoid valve. The ECM grounds the EVAP 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 EVAP vent solenoid valve as ON or OFF.

Conditions for Running the DTC

DTCs P0449, P0498 and P0499 run 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

DTCs P0449, P0498 and P0499 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0449, P0498 and P0499 are Type B DTCs.

Reference Information
Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams
Description and Operation

Evaporative Emission Control System Description Evaporative Emission Control System Description

Hybrid Modes of Operation Description Hybrid Modes of Operation Description
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
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. Service Mode Active, command the EVAP vent solenoid valve ON and OFF with a scan tool. Listen for a click when the valve operates.
2. 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.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the Q13 evaporative emission vent solenoid valve.
2. Service Mode Active, 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 all components connected to the voltage supply circuit and replace as necessary.

3. Connect a test lamp between the voltage supply circuit terminal 2 and the control circuit terminal 1.
4. Command the EVAP 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, test or replace the EVAP vent solenoid valve.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Evaporative Emission Canister Vent Solenoid Valve Replacement Service and Repair
* Control Module References Control Module References for ECM replacement, setup, and programming