E.C.C. DESCRIPTION (Models with catalyzer) — Air-fuel Ratio Control
EF & EC-35prose procedureApplies to GA13DS, GA14DS & GA16DS engines with catalyzer. Crank angle sensor and boost pressure sensor inputs apply to models with E.G.R.; ignition coil and vacuum switch inputs apply to models without E.G.R.
GA13DS, GA14DS & GA16DS
Air-fuel Ratio Control
There are two ways to control the air-fuel ratio. These are open loop control and closed loop control, which are switched back and forth by the signal of water temperature, engine rpm, exhaust gas sensor signal, manifold vacuum and so on.
OPEN-LOOP CONTROL
For improved driveability, air fuel ratio solenoid is controlled by open-loop control under the following conditions. With open-loop control, the air-fuel ratio is determined by the E.C.C. control unit, corresponding to the condition as shown below:
Open-loop control conditions
a
ConditionWhen starting engine
b
ConditionWhen engine is cold
c
ConditionDuring deceleration (Fuel cut system is in operation.)
d
ConditionWhen driving at high speeds
e
ConditionAt full throttle
f
ConditionWhen exhaust gas sensor in not activated
g
ConditionWhen engine is idling