Symptoms

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

Possible Causes

- Damage harness or connectors to the Purge Control Valve - The valve circuit is open or shorted - EVAP canister purge volume control solenoid valve may be faulty

When Detected

An excessively high voltage signal is sent to ECM through the valve

Tech Notes

It's a very common problem with Nissan vehicles. If the harness are not damage, it's very likely that the problem is the canister purge volume control solenoid valve.

Description

This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass passage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor from the EVAP canister is regulated as the air flow changes. The 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 ECM. The longer the ON pulse, the greater the amount of fuel vapor that will flow through the valve.