
ENGINE AND EMISSION CONTROL SYSTEM 6E1-7
ELECTRONIC CONTROL SYSTEM
The electronic control system consists of 1) various sensors which detect the state of engine and driving condi-
tions, 2) ECM which controls various devices according to the signals from the sensors and 3) various controlled
devices.
Functionally, it is divided into nine sub systems :
Fuel injection control system
Idle speed control system
Fuel pump control system
A/C control system (if equipped)
Radiator fan control system
EGR system (if equipped)
Evaporative emission control system
Oxygen sensor heater control system (if equipped)
Ignition control system
Also, with A/T model, ECM sends throttle valve opening signal and coolant temp. signal to transmission control
module to control A/T.
INFORMATION SENSORS CONTROL DEVICES OTHERS
1. MAP sensor a : Fuel injector A : ECM
2. TP sensor b : EVAP canister purge valve B : Main relay
3. IAT sensor c : Fuel pump relay C : EVAP canister
4. ECT sensor d : EGR valve (step motor) (if equipped) D : Monitor connector
5. Heated oxygen sensor-1 (if equipped) e : Malfunction indicator lamp E : Data link connector
5-1. Heated oxygen sensor-2 (if equipped) f : Ignition coil assembly F : A/C EVAP thermistor (if equipped)
6. VSS g : Radiator fan control relay G : TCM (A/T)
7. Transmission range switch (A/T) h : IAC valve
8. Battery i : Immobilizer indicator lamp
9. CMP sensor
10. CKP sensor
11. Fuel level sensor (gauge) (in fuel tank)
12. Stop lamp switch
13. Knock sensor (if equipped)

ENGINE AND EMISSION CONTROL SYSTEM 6E1-13
ECM TERMINAL ARRANGEMENT TABLE
For TYPE A (Refer to NOTE in page “ECM INPUT/OUTPUT CIRCUIT DIAGRAM” for applicable model.)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
C421 BLK/ORN Ground for ECM
C4112––
2 BLK Ground for drive circuit 13–Heated oxygen sensor-2
3 BLK/ORN Ground for drive circuit 14 LT BLU“D”, “2”, “L”-range ID-UP signal
4 BLU/BLK Canister purge valve 15 RED“R”-range signal
5 WHT/BLK Coolant temp. signal output 16 YEL/GRN A/C SW signal
6 GRN/RED IAC valve 17 BRN/YEL EGR valve (stepper motor coil 4)
7 RED/BLU Heater of HO2S-1 18 BLU Radiator fan relay 1
8 BLU/ORN No.4 fuel injector 19 PNK Fuel pump relay
9 BLU/YEL No.1 fuel injector 20––
10 ORN Ground for sensor circuit 21 PPL Throttle opening signal output for A/T
11 RED/YEL CMP sensor 22 YEL/RED Fuel level gauge
12 RED Knock sensor (if equipped) 23 BLK/WHT TCM serial data line
13 WHTHeated oxygen sensor-1
(if equipped)
24––
CO adjusting resistor
(if equipped)
14 LT GRN Coolant temp. sensor
15 LT GRN/BLK Intake air temp. sensor
G021 PPL/WHT Malfunction indicator lamp
16 WHT/GRN Test switch terminal (if equipped) 2 PPL Vehicle speed sensor
17 RED/BLK Electric load (+) 3 PPL/YEL Radiator fan relay 2
18 PNK/GRN A/C switch 4––
19 GRN/WHTIG coil assembly for No.2 and 3 spark
plugs5 BLU Data link connector
20 GRN/YELIG coil assembly for No.1 and 4 spark
plugs6 BLK/WHT Ignition switch signal
21 BLU/WHT No.2 fuel injector 7 YEL Data link connector
22 GRY/RED Power supply for sensor 8––
23 YEL/BLK CKP sensor (+) 9 GRN/WHTStop lamp switch (Brake pedal
switch)
24––10 ORN GND for sensor
25–Ground for sensor shield wire 11––
26 RED/WHT MAP sensor 12 PNKImmobilizer indicator lamp
(if equipped)
27 PPL/WHTDiagnosis switch terminal
(if equipped)13 PNK/BLU Electrical load (-)
28 PNK/BLU Duty output terminal (if equipped) 14 WHT/BLK A/C evaporator temp. sensor
29 BRN Heater of HO2S-2 15––
30 GRN/BLK Heated oxygen sensor-2 16 BRN Tachometer signal
31 BLU/RED No.3 fuel injector 17 WHT/RED Backup power source
C411 PNK/BLK A/C compressor clutch
2 GRN EGR valve (stepper motor coil 1)
3 GRY/BLU Throttle position (TP) sensor
4–Heater of HO2S-2
5 BLK/RED Power source
6 BLK/RED Power source
7 BLK/YEL Engine start signal
8 WHT/RED EGR valve (stepper motor coil 3)
9 GRN/ORN EGR valve (stepper motor coil 2)
10 BRN/WHT Ground for main relay
11––
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
NOTE:
For abbreviation of wire color, refer to Section 0A.

6E1-14 ENGINE AND EMISSION CONTROL SYSTEM
For TYPE B (Refer to NOTE in page “ECM INPUT/OUTPUT CIRCUIT DIAGRAM” for applicable model.)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
C421 BLK/ORN Ground for ECM
C4112––
2 BLK Ground for drive circuit 13––
3 BLK/ORN Ground for drive circuit 14 PPL/WHT Diagnosis switch terminal
4 BLU/BLK Canister purge valve 15 WHT/GRN Test switch terminal
5––16 YEL/GRN A/C SW signal
6 GRN/RED IAC valve 17 RED/YEL
Electric load (+)
7 RED/BLU Heater of HO2S-1 18 BLU Radiator fan relay 1
8 BLU/ORN No.4 fuel injector 19 PNK Fuel pump relay
9 BLU/YEL No.1 fuel injector 20 BLK/YEL
Cranking signal
10 ORN Ground for sensor circuit 21 GRN/WHTStop lamp switch (Brake pedal
switch)
11 RED/YEL CMP sensor 22 PPL Vehicle speed sensor
12 Or Grand for shield wire 23––
13 WHTHeated oxygen sensor-1
(if equipped)
24––
CO adjusting resistor
(if equipped)
14 LT GRN Coolant temp. sensor
15 LT GRN/BLK Intake air temp. sensor
G021 WHT/BLK A/C evaporator temp. sensor
16 GRY/BLU Throttle position (TP) sensor 2 RED“R” range signal
17 WHT/RED EGR valve (stepper motor coil 3) 3––
18 GRY EGR valve (stepper motor coil 1) 4––
19 GRN/WHTIG coil assembly for No.2 and 3 spark
plugs5 WHT/BLK Engine coolant temp. signals output
20 GRN/YELIG coil assembly for No.1 and 4 spark
plugs6 GRN/RED“D”, “2”, “L” range ID-UP signal
21 BLU/WHT No.2 fuel injector 7 YEL Data link connector
22 GRY/RED Power supply for sensor 8––
23 YEL/BLK CKP sensor (+) 9 PPL/WHT Malfunction indicator lamp
24––10––
25 RED Knock sensor (if equipped) 11 BLU
Data link connector
26 RED/WHT MAP sensor 12––
27––13 PNK/BLU Electrical load (-)
28 BRN/YEL EGR valve (stepper motor coil 4) 14 ORN Ground for sensor
29 GRN/ORNEGR valve (stepper motor coil 2)
15 PPL
Throttle opening signal output for
A/T
30 PNK/GRN A/C switch 16 BRN Tachometer signal
31 BLU/RED No.3 fuel injector 17––
C411 PNK/BLK A/C compressor clutch
2––
3––
4––
5 BLK/RED Power source for drive circuit
6 BLK/RED Power source for main circuit
7 WHT/RED Power source for memory circuit
8 PNK/BLU Duty signal output terminal
9 GRN/RED Radiator fan drive relay No.2
10 BRN/WHT Ground for main relay
11 BLK/WHT
Ignition switch signal
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
NOTE:
For abbreviation of wire color, refer to Section 0A.

ENGINE AND EMISSION CONTROL SYSTEM 6E1-15
ON-VEHICLE SERVICE
ACCELERATOR CABLE ADJUSTMENT
With accelerator pedal depressed fully (1), check clearance
between throttle lever (2) and lever stopper (3) (throttle body)
which should be within following specification.
If measured value is out of specification, adjust it to specification
with cable adjusting nut (4).
Accelerator cable adjustment clearance (with pedal
depressed fully)
“a” : 0.5 – 2.0 mm (0.02 – 0.07 in.)
IDLE SPEED/IDLE AIR CONTROL (IAC) DUTY
INSPECTION
Before idle speed/IAC duty check, make sure of the following.
Lead wires and hoses of Electronic Fuel Injection and engine
emission control systems are connected securely.
Accelerator cable has some play, that is, it is not tight.
Valve lash is checked and adjusted according to mainte-
nance schedule.
Ignition timing is within specification.
All accessories (wipers, heater, lights, A/C, etc.) are out of
service.
Air cleaner has been properly installed and is in good condi-
tion.
No abnormal air inhaling from air intake system.
After above items are all confirmed, check idle speed and IAC
duty as follows.
NOTE:
Before starting engine, place transmission gear shift
lever in “Neutral” (shift selector lever to “P” range for A/T
vehicle), and set parking brake and block drive wheels.

6E1-18 ENGINE AND EMISSION CONTROL SYSTEM
AIR INTAKE SYSTEM
THROTTLE BODY
ON-VEHICLE INSPECTION
Check that throttle valve lever (1) moves smoothly.
REMOVAL
1) Disconnect negative cable at battery.
2) Drain cooling system.
3) Disconnect accelerator cable (1) from throttle valve lever.
4) Disconnect IAT sensor connector and remove air cleaner
assembly with air cleaner outlet hose.
1. Throttle body 4. Gasket 7. TP sensor screws
2. Throttle stop screw 5. Idle air control valve Tightening torque
3. TP sensor 6. IAC valve screws Do not reuse.

ENGINE AND EMISSION CONTROL SYSTEM 6E1-19
5) Disconnect electric connector from TP sensor (1) and IAC
valve (2).
6) Remove throttle body from intake manifold.
7) Disconnect engine coolant hoses from throttle body.
DISASSEMBLY
Remove TP sensor and IAC valve from throttle body.
CLEANING
Clean throttle body bore (1) and idle air passage (2) by blowing
compressed air.
REASSEMBLY
1) Install IAC valve to throttle body referring to “IAC valve Instal-
lation” section.
2) Install TP sensor to throttle body referring to “TP sensor
Installation” section.
INSTALLATION
1) Clean mating surfaces and install throttle body gasket to
intake manifold.
Use new gasket.
2) Connect engine coolant hoses.
NOTE:
While disassembling and assembling throttle body, use
special care not to deform levers on throttle valve shaft
or cause damage to any other parts.
NOTE:
TP sensor, idle air control valve or other components
containing rubber must not be placed in a solvent or
cleaner bath. A chemical reaction will cause these parts
to swell, harden or get distorted.

6E1-20 ENGINE AND EMISSION CONTROL SYSTEM
3) Install throttle body (1) to intake manifold.
4) Connect connector to TP sensor (2) and IAC valve (3)
securely.
5) Connect accelerator cable and adjust cable play to specifica-
tion.
6) Install air cleaner assembly with air cleaner outlet hose and
connect IAT sensor connector.
7) Refill cooling system.
8) Connect negative cable at battery.
IDLE AIR CONTROL VALVE (IAC VALVE)
REMOVAL
1) Remove throttle body from intake manifold referring to
“Throttle Body Removal” section.
2) Remove IAC valve from throttle body.
INSPECTION
1) Connect each connector to IAC valve (1), TP sensor and IAT
sensor.
2) Check that rotary valve (2) of lAC valve opens and closes
once and then stops in about 60 ms as soon as ignition
switch is turned ON.
INSTALLATION
1) Install new gasket (2) to IAC valve (1).
2) Install IAC valve (1) to throttle body (3).
Tighten IAC valve screws to specified torque.
Tightening torque
IAC valve screw (a) : 3.5 N·m (0.35 kg-m, 2.5 lb-ft)
3) Install throttle body to intake manifold referring to “Throttle
Body Installation” section.
NOTE:
This check should be performed by two people, one
person turns on ignition switch while the other checks
valve operation.
As valve operation is momentary, it may be over-
looked. To prevent this, perform this operation check 3
times or more continuously.
If rotary valve of lAC valve does not operate at all,
check wire harness for open and short. If wire harness
is in good condition, replace lAC valve and recheck.

6E1-28 ENGINE AND EMISSION CONTROL SYSTEM
THROTTLE POSITION SENSOR (TP SENSOR)
INSPECTION
1) Disconnect negative cable at battery and connector from IAT
sensor.
2) Remove air cleaner assembly with air cleaner outlet hose
and disconnect TP sensor connector.
3) Using ohmmeter, check resistance between terminals under
each condition given in table below.
If check result is not satisfactory, replace TP sensor.
TP sensor resistance
4) Connect TP sensor connector securely.
5) Connect negative cable to battery.
REMOVAL
1) Disconnect battery negative cable at battery.
2) Remove throttle body from intake manifold referring to
“Throttle Body Removal” in this section.
3) Remove TP sensor from throttle body.
INSTALLATION
1) Install TP sensor (1) to throttle body.
Fit TP sensor to throttle body in such way that its holes (3)
are a little away from TP sensor screw holes (2) as shown in
left figure and turn TP sensor clockwise so that those holes
align (4).
Tightening torque
TP sensor screw (a) : 2.5 N·m (0.25 kg-m, 1.8 lb-ft)
2) Connect connector to TP sensor securely.
3) Connect battery negative cable to battery.TERMINALS RESISTANCE
Between 1 and
3 terminals4.0 – 6.0 k
Ω
Between 2 and
3 terminals20
Ω – 6.0 k
Ω, varying according to throt-
tle valve opening.
NOTE:
There should be more than 2 k
Ω resistance difference
between when throttle valve is at idle position and when
it is fully open.
1. Reference voltage terminal
2. Output voltage terminal
3. Ground terminal