Fail-safe System (Cont'd)
EF & EC-223prose procedureGA16DE engine.
ENGINE AND EMISSION CONTROL SYSTEM DESCRIPTION
Fail-safe System (Cont'd)
AIR FLOW METER MALFUNCTION
If the air flow meter output voltage is above or below the specified value, the E.C.U. senses an air flow meter malfunction. In case of a malfunction, the throttle sensor substitutes for the air flow meter.
Though air flow meter is malfunctioning, it is possible to drive the vehicle and start the engine. But engine speed will not rise more than 2,400 rpm in order to inform the driver of fail-safe system operation while driving.
Operation
Air flow meter malfunction operation
Stopped
Starter switchANY
Fail-safe systemDoes not operate
Fail-safe functioning
Cranking
Starter switchON
Fail-safe systemOperates
Fail-safe functioningEngine will be started by a pre-determined injection pulse on E.C.U.
Running
Starter switchOFF
Fail-safe systemOperates
Fail-safe functioningEngine speed will not rise above 2,400 rpm
ENGINE TEMPERATURE SENSOR MALFUNCTION
When engine temperature sensor output voltage is below or above the specified value, water temperature is fixed at the preset value as follows:
Operation
Engine temperature sensor malfunction operation
Just as ignition switch is turned ON or Start
Engine temperature decided40°C (104°F)
More than 4 minutes after ignition ON or Start
Engine temperature decided80°C (176°F)
Except as shown above
Engine temperature decided40 - 80°C (104 - 176°F) (Depends on the time)
THROTTLE SENSOR MALFUNCTION
Description
When the output signal of throttle sensor is abnormal the E.C.U. judges it as a malfunctioning of throttle sensor. The E.C.U. does not use the throttle sensor signal, but judges the idle position by the amount of fuel injected and the engine rpm.
Operation
Throttle sensor malfunction operation
When engine is idling
Normal
When accelerating
Poor acceleration