Vapor absorber tank (EVAP)
The EVAP canister can temporarily store fuel vapor from the fuel tank until it can be purged from the EVAP canister into the engine and burned.
Vapor canister purge valve (EVAP)
When the coolant temperature is below 60°C, the ECM turns off the EVAP canister purge valve, which shuts off vacuum to the EVAP canister.
Control system
EVAP absorber control minimizes the amount of fuel vapors escaping into the atmosphere. Vapors from the fuel tank are temporarily stored in the EVAP canister until they can be directed from the canister to the engine cylinders and burned there.
The EVAP canister is purged by introducing fresh air into it, which is then directed to the intake manifold.
The vacuum required for purge is controlled by the EVAP canister purge valve, which is open when the coolant temperature is above 60°C.
When the vapor pressure in the fuel tank is higher than the EVAP two-way valve setting, the valve opens and controls the flow of fuel vapor into the canister.
EGR system reduces nitrogen oxides (NOx) in the exhaust gases by bypassing part of the exhaust gases through the EGR valve and the intake manifold into the combustion chamber. The ECM memory contains ideal EGR valve positions for various operating conditions.
The EGR valve position sensor detects the EGR valve lift and sends this information to the ECM. The ECM then compares this value with the optimum lift value stored in its memory (based on signals received from other sensors). If there is a difference between these two signals, the ECM cuts off power to the EGR valve.