P0448
DTC P0448
CIRCUIT DESCRIPTION
The Evaporative Emission (EVAP) System is used to prevent fuel vapors from venting to the atmosphere. The EVAP canister vent solenoid is normally open. This allows ambient air to flow through the EVAP canister to the fuel tank so that atmospheric pressure can be maintained in the fuel tank. The engine control module (ECM) controls the EVAP canister vent solenoid by providing ground to the EVAP canister vent solenoid control circuit. The ECM monitors the EVAP canister vent solenoid control circuit for low and high voltage faults. If the ECM detects that the voltage of the EVAP canister vent solenoid control circuit is above a predetermined threshold when the EVAP canister vent solenoid is commanded ON, DTC P0448 sets.
CONDITIONS FOR RUNNING THE DTC
- DTC P0447 is not set.
- The engine speed is more than 40 RPM.
- The battery voltage is more than 8.05 volts and less than 18 volts.
- The vehicle is moving.
CONDITIONS FOR SETTING THE DTC
- The voltage of the EVAP canister vent solenoid control circuit is above 1.25 volts when the EVAP canister vent solenoid is commanded ON.
- The above condition is met for more than 0.5 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
- The driver information center, if equipped, may display a message.
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.
TEST
