• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | P0498 | P0498 | -- | -- |
EVAP Canister Vent Solenoid Valve Control Circuit | P0498 | P0498 | P0499 | -- |
The evaporative emission (EVAP) vent solenoid valve is used for EVAP system diagnostics. The EVAP vent solenoid valve is a normally open valve. Ignition voltage is supplied directly to the EVAP vent solenoid valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver.
• | The ignition is ON or the engine is operating. |
• | The DTCs runs continuously once the above conditions are met. |
The ECM detects the EVAP vent solenoid valve control circuit is open.
The ECM detects the EVAP vent solenoid valve control circuit is shorted to ground or voltage.
• | DTC P0498 and P0499 are Type A DTCs. |
• | The EVAP system will only purge during open loop. |
DTC P0498 and P0499 are Type A DTCs.
Evaporative Emission Control System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary. |
⇒ | If the test lamp is always ON, test for a short to ground on the control circuit. If the circuit tests normal, replace the ECM. |
⇒ | If the test lamp is always OFF, test for a short to voltage or an open/high resistance on the control circuit. If the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the EVAP vent solenoid valve. |
⇒ | If not the specified value, replace the EVAP vent solenoid valve. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |