Purge valve

Purge valve

The vehicle is equipped with an evaporative emission control system designed to prevent vapour loss from the fuel tank. Fuel tank vapour is passed through a charcoal canister which traps fuel vapour. The vapours trapped by the charcoal canister is drawn in to the engine through the purge valve and burnt in the combustion chamber.

The ECM controls the opening of the purge valve to allow venting of the charcoal canister. The ECM pulses the purge valve open for short periods when the engine has reached normal operating temperature and is turning at a speed over 1700 rpm. This is done to ensure that the fuelling of the engine is not adversely affected during warm up or at idle. During purge valve operation, the ECM monitors HO2S signals. If opening the purge valve causes the HO2S signal to indicate a leaner mixture, the ECM assumes that the charcoal canister is empty. When the charcoal canister is monitored to be empty, the purge valve is opened to prevent a build up of fuel vapour in the canister. With the purge valve open, unmetered air is drawn into the engine through the charcoal canister. The ECM uses the signal from the HO2S’s to corrects the fuelling.

Inertia switch

Power to the fuel pump is supplied via the inertia switch. In the event of extreme deceleration, as would be experienced in a collision, the inertia switch trips, isolating electrical supply from the fuel pump. The switch is reset by pressing the rubber button on top of the switch.