2005 SCION tC (EWD572U)
65
2. Control System
∗ SFI system
The SFI system monitors the engine condition through the signals input from each sensor to the engine control module.
And the control signal is output to TERMINALS #1, #2, #3 and #4 of the engine control module to operate the fuel
injector (Inject the fuel). The SFI system controls the fuel injection operation by the engine control module in response to
the driving conditions.
∗ ESA system
The ESA system monitors the engine condition through the signals input to the engine control module from each sensor.
The best ignition timing is decided according to this data and the memorized data in the engine control module and the
control signal is output to TERMINALS IGT1, IGT2, IGT3, IGT4. This signal controls the igniter (Ignition coil) to provide
the best ignition timing for the driving conditions.
∗ Heated oxygen sensor heater control system
The heated oxygen sensor heater control system turns the heater on when the intake air volume is low (Temp. of
exhaust emissions is low), and warms up the heated oxygen sensor to improve detection performance of the sensor.
The engine control module evaluates the signals from each sensor, and outputs current to TERMINAL HT1B to control
the heater.
3. Diagnosis System
With the diagnosis system, when there is a malfunction in the engine control module signal system, the malfunctioning
system is recorded in the memory. The malfunctioning system can be found by reading the code displayed by the
malfunction indicator lamp.
4. Fail–Safe System
When a malfunction has occurred in any system, if there is a possibility of engine trouble being caused by continued control
based on the signals from that system, the fail–safe system either controls the system by using data (Standard values)
recorded in the engine control module memory or else stops the engine.
E4 (A), E5 (B), E6 (C), E7 (D), E8 (E) Engine Control Module
BATT–E1 : Always 9.0–14.0 volts
VC–E2 : 4.5–5.5 volts (Ignition SW at ON position)
VG–E2G : 1.1–1.5 volts (Engine idling and A/C SW off)
THA–E2 : 0.5–3.4 volts (Engine idling and intake air temp. 20°C, 68°F)
THW–E2 : 0.2–1.0 volts (Engine idling and coolant temp. 80°C, 176° F)
IGF1–E1 : 4.5–5.5 volts (Ignition SW at ON position)
Pulse generation (Engine idling)
TACH–E1 : Pulse generation (Engine idling)
STA–E1 : 6.0 volts or more (Engine cranking)
FC–E01 : 9.0–14.0 volts (Ignition SW at ON position)
SPD–E1 : Pulse generation (Ignition SW on and rotate driving wheel slowly)
W–E01 : Below 3.0 volts (Ignition SW at ON position)
NSW–E1 : 9.0–14.0 volts (Ignition SW on and other shift position in P or N position)
0–3.0 volts (Ignition SW on and shift position in P or N position)
PRG–E01 : 9.0–14.0 volts (Ignition SW at ON position)
STP–E1 : 7.5–14.0 volts (Ignition SW on and brake pedal depressed)
Below 1.5 volts (Ignition SW on and brake pedal released)
KNK1–E1 : Pulse generation (Engine idling)
HA1A–E04 : Below 3.0 volts (Engine idling)
IGSW–E1 : 9.0–14.0 volts (Ignition SW at ON position)
MREL–E1 : 9.0–14.0 volts (Ignition SW at ON position)
G2+, NE+ –NE– : Pulse generation (Engine idling)
HT1B–E1 : 9.0–14.0 volts (Engine idling)
Below 3.0 volts (Ignition SW at ON position)
A1A+ –E1 : 3.3 volts (Ignition SW at ON position)
A1A– –E1 : 3.0 volts (Ignition SW at ON position)
OX1B–E1 : Pulse generation (Maintain engine speed at 2500 rpm for 90 sec. after warming up)
IGT1, IGT2, IGT3, IGT4–E1 : Pulse generation (Engine idling)
#1, #2, #3, #4–E01 : 9.0–14.0 volts (Ignition SW at ON position)
Pulse generation (Engine idling)
Service Hints
To Next Page
Loading...
