ENGINE AND EMISSION CONTROL SYSTEM 6E1-5
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 16. Immobilizer indicator lamp (if equipped) 31. Monitor connector (vehicle without immobi-
lizer indicator lamp)
2. EVAP canister purge valve 17. Knock sensor (if equipped) 31-1. Diagnosis switch terminal (vehicle without
immobilizer indicator lamp)
3. IAT sensor 18. ECT sensor 31-2. Test switch terminal (vehicle without immobi-
lizer indicator lamp)
4. TP sensor 19. CMP sensor 31-3. Duty output terminal (vehicle without immobi-
lizer indicator lamp)
5. IAC valve 20. CKP sensor 32. Stop lamp
6. MAP sensor 21. VSS 33. Stop lamp switch
7. EGR valve (if equipped) 22. Radiation fan 34. ECM
8. EVAP canister 23. Malfunction indicator lamp in combination meter 35. Barometric pressure sensor (if equipped)
9. Tank pressure control valve (built-in fuel pump) 24. Park/Neutral position switch (A/T) 36. Battery
10. Fuel pump (with pressure regulator) 25. Ignition switch 37. CO adjusting resistor (if equipped)
11. Fuel level sensor (vehicle with immobilizer indi-
cator lamp)26. Starter magnetic switch 38. A/C compressor clutch (if equipped)
12. Ignition coil assembly 27. TCM 39. A/C switch (if equipped)
13. Fuel injector 28. Transmission range switch (A/T) 40. A/C evaporator temp. sensor (if equipped)
14. Heated Oxygen Sensor (HO2S)-1
(if equipped)29. DLC 41. Immobilizer control module (if equipped)
15. Heated Oxygen Sensor (HO2S)-2
(if equipped)30. Electric load 42. Main relay
54
2
1
6
3
7
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)
6E1-8 ENGINE AND EMISSION CONTROL SYSTEM
ENGINE & EMISSION CONTROL INPUT/OUTPUT TABLE
INPUTOUTPUT
ELECTRIC CONTROL DEVICE
FUEL LEVEL SENSOR (VEHICLE WITH IMMOBILIZER INDICATOR LAMP) For detecting fuel level DIAGNOSIS SWITCH (VEHICLE WITHOUT IMMOBILIZER INDICATOR LAMP)
BAROMETRIC PRESSURE SENSOR (VEHICLE WITH EGR VALVE)
STOP LAMP SWITCH
START SWITCH
IGNITION SWITCH
LIGHTING SWITCH
REAR DEFOGGER SWITCH
BLOWER SWITCH
A/C SWITCH
A/C EVAP TEMP. SENSOR
VSS
HEATED OXYGEN SENSOR-1
(VEHICLE WITH EGR VALVE)
HEATED OXYGEN SENSOR-2
(VEHICLE WITH IMMOBILIZER INDICATOR LAMP)For detecting deterioration of
three way catalytic convertor
IAT SENSOR
ECT SENSOR
TP SENSOR
MAP SENSOR
CMP SENSOR
CKP SENSOR
TEST SWITCH TERMINAL
(VEHICLE WITHOUT IMMOBILIZER INDICATOR LAMP)
KNOCK SENSOR (VEHICLE WITH EGR VALVE)
FUEL PUMP RELAY
FUEL INJECTOR
HO2S HEATER
IAC VALVE
IGNITION COIL WITH IGNITER
EGR VALVE (IF EQUIPPED)
EVAP CANISTER PURGE VALVE
A/C COMPRESSOR CLUTCH
RADIATOR FAN RELAY
MIL
MAIN RELAY
TRANSMISSION CONTROL MODULE SIGNAL FROM SENSOR, SWITCH AND CONTROL MODULE
6E1-10 ENGINE AND EMISSION CONTROL SYSTEM
1. CKP sensor 20. Blank 39. Ignition coil assembly (for No.1 and No.4 spark plugs)
2. CMP sensor 21. A/C switch 40. Ignition coil assembly (for No.2 and No.3 spark plugs)
3. VSS 22. A/C pressure switch 41. Stop lamp switch
4. MAP sensor 23. Immobilizer control module 42. Stop lamp
5. Knock sensor (if equipped) 24. Data link connector 43. Lighting switch
6. TP sensor 25. Injector No.1 44. Position lamp
7. ECT sensor 26. Injector No.2 45. Rear defogger switch
8. IAT sensor 27. Injector No.3 46. Rear defogger
9. Heated oxygen sensor-1 (if equipped) 28. Injector No.4 47. A/C compressor clutch (if equipped)
10. Heated oxygen sensor-2 (if equipped) 29. IAC valve 48. Ignition switch
11. A/C evaporator temp. sensor 30. EVAP canister purge valve 49. Main relay
12. Combination meter 31. Fuel pump relay 50. Transmission range switch (A/T)
13. Fuel level sensor (vehicle with immobilizer
indicator lamp)32. Fuel pump 51. Starting motor
14. TCM 33. Radiator fan relay 52. Shield wire
15. Transmission range switch 34. Radiator fan motor 53. Main fuse
16. ABS control module 35. EGR valve (if equipped) 54. Barometric pressure sensor
17. CO adjusting resistor (if equipped) 36. Malfunction indicator lamp 55. Immobilizer indicator lamp (if equipped)
18. Heater fan motor 37. Tachometer 56. Engine ground
19. Heater fan switch 38. Monitor connector (vehicle without immo-
bilizer indicator lamp)57. Body ground
6E1-12 ENGINE AND EMISSION CONTROL SYSTEM
1. CKP sensor 20. Blank 39. Ignition coil assembly (for No.1 and No.4 spark plugs)
2. CMP sensor 21. A/C switch 40. Ignition coil assembly (for No.2 and No.3 spark plugs)
3. VSS 22. A/C pressure switch 41. Stop lamp switch
4. MAP sensor 23. Immobilizer control module 42. Stop lamp
5. Knock sensor (if equipped) 24. Data link connector 43. Lighting switch
6. TP sensor 25. Injector No.1 44. Position lamp
7. ECT sensor 26. Injector No.2 45. Rear defogger switch
8. IAT sensor 27. Injector No.3 46. Rear defogger
9. Heated oxygen sensor-1 (if equipped) 28. Injector No.4 47. A/C compressor clutch (if equipped)
10. Blank 29. IAC valve 48. Ignition switch
11. A/C evaporator temp. sensor 30. EVAP canister purge valve 49. Main relay
12. Combination meter 31. Fuel pump relay 50. Transmission range switch (A/T)
13. Fuel level sensor (vehicle with immobilizer
indicator lamp)32. Fuel pump 51. Starting motor
14. TCM 33. Radiator fan relay 52. Shield wire
15. Transmission range switch 34. Radiator fan motor 53. Main fuse
16. ABS control module 35. EGR valve (if equipped) 54. Barometric pressure sensor
17. CO adjusting resistor (if equipped) 36. Malfunction indicator lamp 55. Immobilizer indicator lamp (if equipped)
18. Heater fan motor 37. Tachometer 56. Engine ground
19. Heater fan switch 38. Monitor connector (vehicle without immo-
bilizer indicator lamp)57. Body ground
6F1-2 IGNITION SYSTEM (ELECTRONIC IGNITION SYSTEM)
GENERAL DESCRIPTION
The ignition system is an electronic (distributorless) ignition system. Its consists of the parts as described below
and has an electronic ignition control system.
ECM
It detects the engine and vehicle conditions through the signals from the sensors, determines the most suit-
able ignition timing and time for electricity to flow to the primary coil and sends a signal to the ignitor (power
unit) in the ignition coil assembly.
Ignition coil assembly (including an igniter)
The ignition coil assembly has a built-in ignitor which turns ON and OFF the current flow to the primary coil
according to the signal from ECM. When the current flow to the primary coil is turned OFF, a high voltage is
induced in the secondary coil.
High tension cords and spark plugs.
CMP sensor (Camshaft position sensor) and CKP sensor (Crankshaft position sensor)
Using signals from these sensors, ECM identifies the specific cylinder whose piston is in the compression
stroke, detects the crank angle and adjusts initial ignition timing automatically.
TP sensor, ECT sensor, MAP sensor and other sensors/switches
Refer to Section 6E1 for details.
Although this ignition system does not have a distributor, it has two ignition coil assemblies (one is for No.1 and
No.4 spark plugs and the other is for No.2 and No.3 spark plugs). When an ignition signal is sent from ECM to
the ignitor in the ignition coil assembly for No.1 and No.4 spark plugs, a high voltage is induced in the secondary
coil and that passes through the high-tension cords and causes No.1 and No.4 spark plugs to spark simulta-
neously. Likewise, when an ignition signal is sent to the ignitor in the other ignition coil assembly, No.2 and No.3
spark plugs spark simultaneously.
SYSTEM COMPONENTS
1. ECM 6. MAP sensor 11. Transmission range switch (A/T)
2. Ignition coil assembly for No.1 and No.4 spark plugs 7. ECT sensor 12. High-tension cords
3. Ignition coil assembly for No.2 and No.3 spark plugs 8. IAT sensor 13. Monitor connector
4. CMP sensor 9. TP sensor 14. Knock sensor (if equipped)
5. CKP sensor 10. VSS 15. Data link connector
6G-2 CRANKING SYSTEM
GENERAL DESCRIPTION
CRANKING CIRCUIT
DIAGNOSIS
DIAGNOSIS TABLE
Possible symptoms due to starting system trouble would be as follows:
Starting motor does not run (or runs slowly)
Starting motor runs but fails to crank engine
Abnormal noise is heard
Proper diagnosis must be made to determine exactly where the cause of each trouble lies.....in battery, wiring
harness, (including starting motor switch), starting motor or engine.
Do not remove motor just because starting motor does not run. Check following items and narrow down scope
of possible causes.
1) Condition of trouble
2) Tightness of battery terminals (including ground cable connection on engine side) and starting motor termi-
nals
3) Discharge of battery
4) Mounting of starting motor
1. Pinion drive lever 5. Plunger 9. Blank
2. Pinion & Over-running clutch 6. Magnetic switch contacts 10. A/T: Transmission range switch (shift lever switch)
3. Magnetic switch 7. Pull-in coil 11. Ignition & Starter switch
4. Hold-in coil 8. Starting motor 12. Battery