THE ENGINE CONTROL SYSTEM UTILIZES A MICROCOMPUTER AND MAINTAINS OVERALL CONTROL OF THE ENGINE,
TRANSMISSION, ETC. AN OUTLINE OF ENGINE CONTROL IS GIVEN HERE.
1. INPUT SIGNAL
(1) ENGINE COOLANT TEMP. (WATER TEMP.) SIGNAL SYSTEM
THE ENGINE COOLANT TEMP. SENSOR (WATER TEMP. SENSOR) DETECTS THE ENGINE COOLANT TEMP. AND HAS A
BUILT–IN THERMISTOR WITH A RESISTANCE WHICH VARIES ACCORDING TO THE ENGINE COOLANT TEMP. (WATER TEMP.)
THUS THE ENGINE COOLANT TEMP. (WATER TEMP.) IS INPUT IN THE FORM OF A CONTROL SIGNAL TO TERMINAL THW OF
THE ENGINE CONTROL MODULE (ECU).
(2) INTAKE AIR TEMP. SIGNAL SYSTEM
THE INTAKE AIR TEMP. SENSOR IS INSTALLED INSIDE THE VOLUME AIR FLOW (AIR FLOW METER) AND DETECTS THE INTAKE
AlR TEMP., WHICH IS INPUT AS A CONTROL SIGNAL TO TERMINAL THA OF THE ENGINE CONTROL MODULE (ECU).
(3) OXYGEN SENSOR SIGNAL SYSTEM
THE OXYGEN DENSITY IN THE EXHAUST EMISSIONS IS DETECTED AND INPUT AS A CONTROL SIGNAL TO TERMINAL OX OF
THE ENGINE CONTROL MODULE (ECU). TO MAINTAIN STABLE DETECTION PERFORMANCE BY THE OXYGEN SENSOR, A
HEATER IS USED FOR WARNING THE SENSOR. THE HEATER IS ALSO CONTROLLED BY THE ENGINE CONTROL MODULE
(ECU) (HT).
(4) RPM SIGNAL SYSTEM
THE CRANKSHAFT POSITION AND ENGINE SPEED ARE DETECTED BY THE PICK–UP COIL INSTALLED INSIDE THE
DISTRIBUTOR, AND ARE INPUT AS CONTROL SIGNALS TO TERMINAL NE OF THE ENGINE CONTROL MODULE (ECU).
(5) THROTTLE SIGNAL SYSTEM
THE THROTTLE POSITION SENSOR DETECTS THE THROTTLE VALVE OPENING ANGLE, WHICH IS INPUT AS A CONTROL
SIGNAL TO TERMINAL VTA OF THE ENGINE CONTROL MODULE (ECU), OR WHEN THE VALVE IS FULLY CLOSED, TO TERMINAL
IDL.
(6) VEHICLE SPEED SIGNAL SYSTEM
THE VEHICLE SPEED SENSOR (SPEED SENSOR), INSTALLED INSIDE THE COMBINATION METER, DETECTS THE VEHICLE
SPEED AND INPUT A CONTROL SIGNAL TO TERMINAL SPD, OF THE ENGINE CONTROL MODULE (ECU).
(7) PARK/NEUTRAL POSITION SW (NEUTRAL START SW) SIGNAL SYSTEM (FOR 2WD)
THE PARK/NEUTRAL POSITION SW (NEUTRAL START SW) DETECTS WHETHER THE SHIFT POSITION IS IN NEUTRAL OR NOT,
AND INPUTS A CONTROL SIGNAL TO TERMINAL NSW OF THE ENGINE CONTROL MODULE (ECU).
(8) BATTERY SIGNAL SYSTEM
VOLTAGE IS CONSTANTLY APPLIED TO TERMINAL BATT OF THE ENGINE CONTROL MODULE (ECU). WHEN THE IGNITION SW
IS TURNED TO ON, VOLTAGE FOR ENGINE CONTROL MODULE (ECU) OPERATION IS APPLIED VIA THE EFI MAIN RELAY TO
TERMINALS +B AND +B1 OF THE ENGINE CONTROL MODULE (ECU).
(9) INTAKE AIR VOLUME SIGNAL SYSTEM
INTAKE AIR VOLUME IS DETECTED BY THE POTENTIOMETER INSTALLED INSIDE THE VOLUME AIR FLOW (AIR FLOW METER)
AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL VS OF THE ENGINE CONTROL MODULE (ECU). INSIDE THE VOLUME AIR
FLOW (AIR FLOW METER) THERE IS ALSO A SW FOR FUEL PUMP OPERATION, AND WHEN THE MEASURING PLATE OPENS
(AIR INTAKE OCCURS), THIS SW TURNS ON AND CURRENT FLOWS TO THE FUEL PUMP TO OPERATE IT.
(10) STOP LIGHT SW SIGNAL SYSTEM
THE STOP LIGHT SW IS USED TO DETECT WHETHER OR NOT THE VEHICLE IS BRAKING AND THE INFORMATION IS INPUT AS
A CONTROL SIGNAL TO TERMINAL STP OF THE ENGINE CONTROL MODULE (ECU).
(11) STA SIGNAL SYSTEM
TO CONFIRM THAT THE ENGINE IS CRANKING, THE VOLTAGE APPLIED TO THE STARTER MOTOR DURING CRANKING IS
DETECTED AND IS INPUT AS A CONTROL SIGNAL TO TERMINAL STA OF THE ENGINE CONTROL MODULE (ECU).
(12) ENGINE KNOCK SIGNAL SYSTEM
ENGINE KNOCKING IS DETECTED BY THE KNOCK SENSOR AND INPUT AS A CONTROL SIGNAL TO TERMINAL KNK OF THE
ENGINE CONTROL MODULE (ECU).
(13) 4WD SIGNAL SYSTEM
WHETHER OR NOT THE VEHICLE IS OPERATING IN 4WD MODE IS DETERMINED, AND A CONTROL SIGNAL IS INPUT TO
TERMINAL 4WD OF THE ENGINE CONTROL MODULE (ECU).

V 3 VOLUME AIR FLOW (AIR FLOW METER)
1–2: OPEN WITH MEASURING PLATE CLOSED
CLOSED WITH MEASURING PLATE OPEN
4–3: 200–400 
5–3: 100–300
6–3: 20–400 (MEASURING PLATE FULLY CLOSED)
20–1000 (MEASURING PLATE FULLY OPEN)
3–7: 10–20 K (–20
C, –4
F)
4–7 K (0
C, 32
F)
2–3 K (20
C, 68
F)
0.9–1.3 K (40
C, 104
F)
0.4–0.7 K (60
C, 140
F)
C 7 CIRCUIT OPENING RELAY
1–2: CLOSED WITH STARTER RUNNING OR MEASURING PLATE (AIR FLOW METER) OPEN
E 4 ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP. SENSOR)
1–2: 10–20 K (–20
C, –4
F)
4–7 K (0
C, 32
F)
2–3 K (20
C, 68
F)
0.9–1.3 K (40
C, 104
F)
0.4–0.7 K (60
C, 140
F)
0.2–0.4 K (80
C, 176
F)
I 8, I 9, I10, I11 INJECTOR
1–2: APPROX. 13.8 
P 1 PARK/NEUTRAL POSITION SW (NEUTRAL START SW)
3–2: CLOSED WITH A/T SHIFT LEVER IN P OR N POSITION
T 1 THROTTLE POSITION SENSOR
3–1: 0.47–6.1 K WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0 MM (0 IN.)
2–1: 2.3 K OR LESS WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0.57 MM (0.0224 IN.)
INFINITY WITH CLEARANCE BETWEEN LEVER AND STOP SCREW 0.85 MM (0.0335 IN.)
3–1: 3.1–12.1 K WITH THROTTLE VALVE FULLY OPEN
4–1: 3.9–9.0 K
ENGINE CONTROL MODULE (ENGINE AND ELECTRONIC CONTROLLED TRANSMISSION ECU (A/T),
ENGINE ECU (M/T))
VOLTAGE AT ENGINE CONTROL MODULE (ECU) CONNECTORS
+B1,+B –E1: 9.0–14.0 VOLTS (IGNITION SW ON)
BATT –E1: 9.0–14.0 VOLTS (ALWAYS)
IDL –E2: 9.0–14.0 VOLTS (IGNITION SW ON AND THROTTLE VALVE OPEN)
VTA –E2: 0.3–0.8 VOLTS (IGNITION SW ON AND THROTTLE VALVE FULLY CLOSED)
3.2–4.9 VOLTS (IGNITION SW ON AND THROTTLE VALVE FULLY OPEN)
IGT –E1: PULSE GENERATION (ENGINE IDLING)
STA –E1: 6.0 VOLTS OR MORE (ENGINE CRANKING)
#10–EO1, #20–EO1: 9.0–14.0 VOLTS (IGNITION SW ON)
W –E1: 9.0–14.0 VOLTS (NO TROUBLE AND ENGINE RUNNING)
VS –E2: 4.0–5.5 VOLTS (IGNITION SW ON AND MEASURING PLATE FULLY CLOSED)
THA –E2: 0.5–3.4 VOLTS (IGNITION SW ON AND INTAKE AIR TEMP. 0
C (32
F) –80
C (176
F)
THW –E2: 0.2–1.0 VOLTS (IGNITION SW ON AND COOLANT TEMP. 60
C (140
F) –120
C (248
F)
VC –E2: 4.5–5.5 VOLTS (IGNITION SW ON)
STP –E2: 7.5–14.0 VOLTS (STOP LIGHT SW ON)
STJ –E1: 9.0–4.0 VOLTS (ENGINE STARTING)
RESISTANCE AT ENGINE CONTROL MODULE (ECU) WIRING CONNECTOR
(DISCONNECT WIRING CONNECTOR)
IDL –E2: INFINITY (THROTTLE VALVE OPEN) 0–100  (THROTTLE VALVE FULLY CLOSED)
VTA –E2: 3.3–10 K (THROTTLE VALVE FULLY OPEN) 0.2–0.8 K (THROTTLE VALVE FULLY CLOSED)
THA –E2: 2–3 K (INTAKE AIR TEMP. 20
C, 68
F)
THW –E2: 0.2–0.4 K (COOLANT TEMP. 80
C, 178
F)
+B –E2: 0.2–0.4 K
VS –E2: 0.02–0.1 K (MEASURING PLATE FULLY CLOSED) 0.02–1.0 K (MEASURING PLATE FULLY OPEN)
NE –E1: 140–180