Downloaded from www.Manualslib.com manuals search engine ENGINE AND EMISSION CONTROL SYSTEM 6E-3
General Description
The engine and emission control system is divided into 4 major sub-systems: air intake system, fuel delivery
system, electronic control system and emission control system.
Air intake system includes air cleaner, throttle body, IAC valve and intake manifold.
Fuel delivery system includes fuel pump, delivery pipe, fuel pressure regulator, etc. Electronic control system
includes ECM, various sensors and controlled devices.
Emission control system includes EGR, EVAP and PCV system.
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Air Intake System
The main components of the air intake system are air cleaner (1), air cleaner outlet hose (2), throttle body (3),
idle air control valve (4) and intake manifold (5).
The air (by the amount corresponding to the throttle valve (6) opening and engine speed) is filtered by the air
cleaner (1), passes through the throttle body (3), is distributed by the intake manifold (5) and finally drawn into
each combustion chamber.
When the idle air control valve (4) is opened according to the signal from ECM, the air (7) bypasses the throttle
valve (6) through bypass passage and is finally drawn into the intake manifold (5).
1. Air Cleaner 17. Knock sensor 31-2. Test switch terminal
(vehicle w/o immobilizer indicator lamp)
2. EVAP canister purge valve 18. ECT sensor 31-3. Duty output terminal
(vehicle w/o immobilizer indicator lamp)
3. IAT sensor 19. CMP sensor 32. Immobilizer indicator lamp (if equipped)
4. TP sensor 20. CKP sensor 33. Stop lamp switch
5. IAC valve 21. VSS 34. ECM
6. MAP sensor 22. A/C condenser fan (if equipped) 35. Barometric pressure sensor
(vehicle with immobilizer indicator lamp)
7. EGR valve (if equipped) 23. Malfunction indicator lamp in combination meter 36. Battery
8. EVAP canister 24. Park/Neutral position switch in TR switch (A/T) 37. Immobilizer control module (if equipped)
9. Tank pressure control valve (built-in fuel pump) 25. Ignition switch 38. ABS control module (if equipped)
10. Fuel pump 26. Starter magnetic switch 39. CO adjusting resistor (if equipped)
11. Fuel level sensor 27. TCM (A/T) 40. Power steering pressure switch
(if equipped)
12. Ignition coil assembly 28. Transmission range switch (A/T) 41. A/C compressor clutch (if equipped)
13. Fuel injector 29. DLC 42. A/C EVAP TEMP. sensor (if equipped)
14. Heated Oxygen Sensor (HO2S)-1 (if equipped) 30. Electric load 43. A/C switch (if equipped)
15. Heated Oxygen Sensor (HO2S)-2 (if equipped) 31. Monitor connector (if equipped)
16. Three way catalytic convertor (if equipped) 31-1. Diagnosis switch terminal
(vehicle w/o immobilizer indicator lamp)
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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 the following sub systems:
Fuel injection control system
Idle speed control system
Fuel pump control system
A/C control system (if equipped)
A/C condenser fan control system
EGR system (if equipped)
Evaporative emission control system
Oxygen sensor heater control system
Ignition control system
Also, with A/T model, ECM sends throttle valve opening signal and over drive cut signal to transmission control
module to control A/T.
NOTE:
The figure shows left-hand steering vehicle. For right-hand steering vehicle, parts with (*) are installed
at the other side.
1. IAT sensor a : Immobilizer indicator lamp (if equipped) A : ECM
2. TP sensor b : A/C condenser fan motor relay (if equipped) B : A/T control module
3. Monitor connector c : Main relay C : EVAP canister
4. CO adjusting resistor (if equipped) d : Fuel pump relay D : DLC
5. CKP sensor e : IAC valve E : ABS control module (if equipped)
6. MAP sensor f : EVAP canister purge valve
7. CMP sensor g : EGR valve (if equipped)
8. Transmission range switch h : Fuel injector
9. VSS i : Ignition coil assemblies
10. HO2S-1 (if equipped) J : MIL
11. HO2S-2 (if equipped)
12. ECT sensor
13. Knock sensor
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ECM TERMINAL ARRANGEMENT TABLE
For TYPE A (See NOTE)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
E191 B Ground for ECM
E187 W Backup power source
2 B/R Ground for drive circuit
8R/GImmobilizer indicator lamp
(if equipped)
3 B/R Ground for drive circuitDuty output terminal (vehicle without
immobilizer indicator lamp)
4 Bl/G Canister purge valve 9––
5 Bl/OrPower steering pressure switch
(if equipped)10 Bl Main relay
6 G/Y IAC valve 11 Br Tachometer
7 P/B Heater of HO2S-1 (if equipped) 12 Y/B Data link connector (5 V)
8 W/B No.4 fuel injector 13 WHeated oxygen sensor-2
(if equipped)
9 R/W No.1 fuel injector 14 W/BIDiagnosis switch terminal
(vehicle without immobilizer indicator
lamp)
10 B/Bl Ground for sensor circuit 15 PTest switch terminal
(vehicle without immobilizer indicator
lamp)
11 W CMP sensor 16 G/W A/C SW signal (if equipped)
12––17 R/Y Lighting switch
13R
R/BlHeated oxygen sensor-1
(if equipped)
CO adjusting resistor (w/o HO2S)18 P/B A/C condenser fan relay (if equipped)
14 G/B ECT sensor 19 W/G Fuel pump relay
15 Lg/B IAT sensor 20 B/Bl Ground for sensor
16 Lg TP sensor 21 B/RThrottle opening signal output for A/T
(A/T)
17 Gr/BIEGR valve (stepper motor coil 3, if
equipped)22 Y/RFuel level gauge (vehicle with immo-
bilizer indicator lamp)
18 GrEGR valve (stepper motor coil 1, if
equipped)23––
19 Br/BIG coil assembly for No.2 and 3 spark
plugs24 Bl/Y Heater blower switch
20 Br/WIG coil assembly for No.1 and 4 spark
plugs
21 R/G No.2 fuel injector
E171––
22 Lg/R Power supply for sensor 2 R R-range signal (A/T)
23 G/R CKP sensor 3––
24––4––
25 W Knock sensor 5 B/Or Overdrive cut signal (A/T)
26 G MAP sensor 6 G/Y D-range idle-up signal (A/T)
27 W/R A/C evaporator temp. sensor 7 G/W Stop lamp switch
28 Gr/BEGR valve (stepper motor coil 4, if
equipped)8––
29 Gr/REGR valve (stepper motor coil 2, if
equipped)9 B/W Ignition switch
30––10––
31 W/G No.3 fuel injector 11 Y Vehicle speed sensor
12 G ABS signal (if equipped)
E181 P A/C compressor clutch (if equipped) 13B/Y (M/T)
B/R (A/T)Engine start signal
2 V/Y Malfunction indicator lamp 14––
3 P/G Data link connector (12 V) 15––
4 R/BI Heater of HO2S-2 (if equipped) 16 R/W Rear defogger switch (if equipped)
5 Bl/B Power source 17 G/RA/T failure signal (A/T) (vehicle with
immobilizer indicator lamp)
6 Bl/B Power source
NOTE:
See NOTE in “ECM INPUT / OUTPUT CIRCUIT DIAGRAM” for applicable model.
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For TYPE B (See NOTE)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
E191 B Ground for ECM
E187 W Backup power source
2 B/R Ground for drive circuit
8R/GImmobilizer indicator lamp
(if equipped)
3 B/R Ground for drive circuitDuty output terminal (vehicle without
immobilizer indicator lamp)
4 Bl/G Canister purge valve 9––
5 Bl/OrPower steering pressure switch
(if equipped)10 Bl Main relay
6 G/Y IAC valve 11 B/W Ignition switch
7 P/B Heater of HO2S-1 (if equipped) 12 R/W Rear defogger switch
8 W/B No.4 fuel injector 13––
9 R/W No.1 fuel injector 14 W/BIDiagnosis switch terminal
(vehicle without immobilizer indicator
lamp)
10 B/Bl Ground for sensor circuit 15 PTest switch terminal
(vehicle without immobilizer indicator
lamp)
11 W CMP sensor 16 G/W A/C SW signal (if equipped)
12––17 R/Y Lighting switch
13R
R/BlHeated oxygen sensor-1
(if equipped)
CO adjusting resistor (w/o HO2S)18 P/B A/C condenser fan relay (if equipped)
14 G/B ECT sensor 19 W/G Fuel pump relay
15 Lg/B IAT sensor 20B/Y (M/T)
B/R (A/T)Engine start signal
16 Lg TP sensor 21 G/W Stop lamp switch
17 Gr/BIEGR valve (stepper motor coil 3, if
equipped)22 Y Vehicle speed sensor
18 GrEGR valve (stepper motor coil 1, if
equipped)23––
19 Br/BIG coil assembly for No.2 and 3 spark
plugs24––
20 Br/WIG coil assembly for No.1 and 4 spark
plugs
21 R/G No.2 fuel injector
E171 W/R A/C evaporator temp. sensor
22 Lg/R Power supply for sensor 2 R R-range signal (A/T)
23 G/R CKP sensor 3––
24––4––
25 W Knock sensor 5 B/Or Overdrive cut signal (A/T)
26 G MAP sensor 6 G/Y D-range idle-up signal (A/T)
27––7 Y/B Data link connector
28 Gr/BEGR valve (stepper motor coil 4, if
equipped)8––
29 Gr/REGR valve (stepper motor coil 2, if
equipped)9 V/Y Malfunction indicator lamp
30––10––
31 W/G No.3 fuel injector 11 P/G Data link connector (12 V)
12 G ABS signal (if equipped)
E181 P A/C compressor clutch (if equipped) 13 Bl/Y Heater blower switch
2––14 B/Bl Ground for sensor
3––15 B/R Throttle opening sensor
4 R/BI Heater of HO2S-2 (if equipped) 16 Br Tachometer
5 Bl/B Power source 17––
6 Bl/B Power source
NOTE:
See NOTE in “ECM INPUT / OUTPUT CIRCUIT DIAGRAM” for applicable model.
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On-Vehicle Service
Accelerator cable adjustment
1) With throttle valve closed, check accelerator pedal play
which should be within following specification.
If measured value is out of specification, adjust it to specifi-
cation with cable adjusting nut (1).
Accelerator pedal play
“a” : 2 – 7 mm (0.08 – 0.27 in.)
2) With accelerator pedal depressed fully, 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 specifi-
cation by changing height of pedal stopper bolt (1).
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.
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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.
1. Throttle body 4. Gasket 7. TP sensor screws
2. Throttle body gasket 5. Idle air control valve Tightening torque
3. TP sensor 6. IAC valve screws Do not reuse
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4) Disconnect air cleaner outlet NO.2 hose (1) from throttle
body.
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
1) 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 “Idle Air Control
Valve” in this section.
2) Install TP sensor to throttle body referring to “Throttle Posi-
tion Sensor” in this section for installation.
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.