Possible causes

– Faulty Evaporative Emission (EVAP) Purge Solenoid Control
– Evaporative Emission (EVAP) Purge Solenoid Control harness is open or shorted
– Evaporative Emission (EVAP) Purge Solenoid Control circuit poor electrical connection

Tech notes

On some Subaru model replacing the PCV valve takes care of the P0459. If the problem persist the Engine Control Module (ECM) may need to be replace.

When is the code detected?

The Engine Control Module (ECM) has detected a high voltage on the canister purge solenoid with the driver commanded on

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0459 SUBARU Description

The Evaporative Emission System (EVAP) canister purge volume control solenoid valve uses a ON/OFF duty to control the flow rate of fuel vapor from the EVAP canister. The EVAP canister purge volume control solenoid valve is moved by ON/OFF pulses from the Engine Control Module (ECM). The longer the ON pulse, the greater the amount of fuel vapor that will flow through the valve.