P0459

DTC P0459

CIRCUIT DESCRIPTION




The Evaporative Emission (EVAP) System is used to prevent fuel vapors from venting to the atmosphere. The EVAP canister purge solenoid valve is normally closed. The engine control module (ECM) controls the EVAP canister purge solenoid valve by providing ground to the EVAP canister purge solenoid valve control circuit. This allows ambient air to be drawn through the EVAP canister to the intake manifold so that the fuel vapors that were stored in the EVAP canister can be consumed by the engine. The ECM monitors the EVAP canister purge solenoid valve control circuit for low and high voltage faults. If the ECM detects that the voltage of the EVAP canister purge solenoid valve control circuit is above a predetermined threshold when the EVAP canister purge solenoid valve is commanded OFF, DTC P0459 sets.

CONDITIONS FOR RUNNING THE DTC
- DTC P0458 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 control circuit voltage of the EVAP canister purge solenoid valve is above 1.25 volts when the EVAP canister purge solenoid valve 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

Steps 1-10: