P0498
DTC P0498CIRCUIT DESCRIPTION
Battery voltage is supplied directly to the evaporative emission (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. If the control module detects low voltage on the control circuit when the driver is commanded OFF, this DTC sets.
The table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister vent solenoid valve.
CONDITIONS FOR RUNNING THE DTC
- The engine speed is more than 40 RPM.
- The system voltage is between 7.5-17.3 volts.
CONDITIONS FOR SETTING THE DTC
- The control module detects less than 4.6 volts on the control circuit when the driver is commanded OFF.
- The fault is present for 0.5 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE DTC
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool.
DIAGNOSTIC AIDS
- EVAP canister vent solenoid valve resistance is 18-27 ohms.
- For intermittent conditions refer to Intermittent Conditions. Intermittent Conditions
- Listen for a click when the valve operates. Ensure that both the ON and the OFF states are commanded. Repeat the commands as necessary.
TEST
