6-122 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE B-4 IDLE AIR CONTROL SYSTEM CHECK
INSPECTION
1. IAC valve 2. Main relay 3. To TCM
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
GRN/RED
BLK/YEL
BRN/WHT
BLK/RED
BLK/RED
ECM
C41-10
C41-6
C41-5
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
3
1
2
C42-6 C41-14 [A]
G02-6 [B]
LT BLU [A]
GRN RED [B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 Check engine idle speed and IAC duty referring
to “Idle Speed/IAC Duty Inspection” in Section
6E1.
Is idle speed within specification?Go to Step 2. Go to Step 4.
2 Is IAC duty within specification in Step 1? Go to Step 3. Check for followings :
Vacuum leak
EVAP canister purge con-
trol system
Clog of IAC air passage
Accessory engine load
Closed throttle position
(TP sensor)
Stuck of PCV valve
3 Is engine idle speed kept specified speed even
with headlight ON?System is in good condi-
tion.Check IAC system for
operation referring to Step
2 of DTC P0505 Diag.
Flow Table.
4 Was idle speed higher than specification in
Step 1?Go to Step 5. Go to Step 8.
6-128 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE B-7 RADIATOR FAN CONTROL SYSTEM CHECK
INSPECTION
1. Radiator fan relay No.1 3. Radiator fan relay No.3 [A] : Case of TYPE A is shown (See NOTE)
2. Radiator fan relay No.2 4. Radiator fan [B] : Case of TYPE B is shown (See NOTE)
BATT
80A30A
15A
BLKBLU/WHT
ECM
BLK/ORN
BLK/ORNC42-1
C42-3
L+
L–
H– H+
BLU
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
C41-18
GRN/RED [B]PPL/YEL [A]
BLK/RED
BLU/WHT
BLU/RED
BLK
BLU
BLU/BLK
PPL/YEL
BLU/REDBLK/YEL
BRN/WHT
1
2
34
G02-3 [A]
C41-9 [B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 Check Fan Control System.
1) Connect scan tool to DLC with ignition switch OFF.
2) Start engine and select “DATA LIST” mode on scan
tool.
3) Warm up engine until coolant temp. is 97.5°C, 208°F or
higher and A/C switch turn OFF. (If engine coolant
temp. does not rise, check engine cooling system or
ECT sensor.) See Fig. 1.
Is radiator cooling fan started when engine coolant temp.
reached above temp.?Radiator cooling fan
control system is in
good condition.Go to Step 2.
2 Check Radiator Fan Relay and Its Circuit.
1) Check DTC and pending DTC with scan tool.
Is DTC P0480 displayed?Go to DTC P0480 Diag.
Flow Table.Go to Step 3.
3 Check Radiator Fan Relays.
1) Turn ignition switch OFF and remove radiator cooling
fan relays. (No.1 – No.3)
2) Check for proper connection to relay at terminals “c”
and “d”.
3) If OK, check that there is continuity between “c” and “d”
when battery is connected to terminals “a” and “b”. See
Fig. 2.
Is check result satisfactory?Go to Step 4. Replace radia-
tor fan relay(s).
ENGINE COOLING 6B-1
6B
SECTION 6B
ENGINE COOLING
CONTENTS
GENERAL DESCRIPTION ...............................6B-2
COOLING SYSTEM CIRCULATION............. 6B-2
COOLANT ..................................................... 6B-3
DIAGNOSIS ......................................................6B-4
DIAGNOSIS TABLE ...................................... 6B-4
SYSTEM CIRCUIT ........................................ 6B-5
SYSTEM CIRCUIT INSPECTION ................. 6B-5
MAINTENANCE................................................6B-6
COOLANT LEVEL CHECK ........................... 6B-6
ENGINE COOLING SYSTEM
INSPECTION AND SERVICE ....................... 6B-7
COOLING SYSTEM FLUSH AND REFILL ... 6B-7
WATER PUMP/GENERATOR DRIVE
BELT TENSION INSPECTION AND
ADJUSTMENT .............................................. 6B-9
ON-VEHICLE SERVICE .................................6B-10SYSTEM COMPONENTS .......................... 6B-10
COOLING SYSTEM DRAINING ................. 6B-11
COOLING SYSTEM REFILL ...................... 6B-11
COOLING WATER PIPES OR HOSES ...... 6B-12
THERMOSTAT ........................................... 6B-12
RADIATOR ................................................. 6B-14
RADIATOR AND CONDENSER
COOLING FAN ........................................... 6B-15
RADIATOR AND CONDENSER
COOLING FAN RELAY .............................. 6B-15
WATER PUMP/GENERATOR
DRIVE BELT ............................................... 6B-15
WATER PUMP............................................ 6B-16
ECT SENSOR............................................. 6B-18
REQUIRED SERVICE MATERIAL................. 6B-18
TIGHTENING TORQUE SPECIFICATION..... 6B-18
6B-4 ENGINE COOLING
DIAGNOSIS
DIAGNOSIS TABLE
Condition Possible Cause Correction
Engine overheats
(It is in case that radia-
tor fan operates)Loose or broken water pump belt Adjust or replace.
Not enough coolant Check coolant level and add as
necessary.
Faulty thermostat Replace.
Faulty water pump Replace.
Dirty or bent radiator fins Clean or remedy.
Coolant leakage on cooling system Repair.
Clogged radiator Check and replace radiator as nec-
essary.
Faulty radiator cap Replace.
Improper ignition timing Adjust.
Dragging brakes Adjust brake.
Slipping clutch Adjust or replace.
Poor charge battery Check and replace as necessary.
Poor generation generator Check and repair.
ECT sensor faulty Check and replace as necessary.
Radiator cooling fan relay No.2 and/or No.3
faultyCheck and replace as necessary.
ECM faulty Check and replace as necessary.
Wiring or grounding faulty Repair and necessary.
Equipped with too much electric load part Dismount.
Radiator cooling fan motor faulty Check and replace as necessary.
Engine overheats
(It is in case that radia-
tor fan won’t operates)Fuse blown Check “RADTR fan” fuse and
check for short circuit to ground.
Radiator cooling fan relay No.1 Check and replace as necessary.
ECT sensor faulty Check and replace as necessary.
Radiator cooling fan motor faulty Check and replace as necessary.
Wiring or grounding faulty Repair as necessary
ECM faulty Check and replace as necessary.
ENGINE COOLING 6B-5
SYSTEM CIRCUIT
SYSTEM CIRCUIT INSPECTION
Refer to “RADIATOR COOLINGFAN CONTROL SYSTEM CHECK” in Section 6
1. Main fuse box 6. ECM main fuse 11. Radiator and condenser cooling fan motor
2. Generator 7. ECM main relay 12. Refrigerant pressure triple switch (if equipped with A/C)
3. Battery 8. Radiator and condenser cooling fan relay No.1 13. ECT sensor
4. Battery fuse 9. Radiator and condenser cooling fan relay No.2 14. ECM
5. RADTR fuse 10. Radiator and condenser cooling fan relay No.3 15. TO A/C switch
ACG
15A 30A
BLU/WHT
BLK/YEL
BLK
BLU
ORN
BLK
BLK
BLUH–
H+
L– L+
GRN/BLK
BLU/BLK
BRN/WHT
YEL/GRN
PNK/GRN
PPL/YEL
LT GRN/BLK
BLK/RED
BLK/RED 80A
145
6
2
3
7
8
9
11
10
13 15
12
14
ENGINE COOLING 6B-15
RADIATOR AND CONDENSER COOLING FAN
Refer to “RADIATOR AND CONDENSER COOLING FAN” in
Section 1B for removal, inspection and installation.
RADIATOR AND CONDENSER COOLING FAN
RELAY
INSPECTION
1) Disconnect negative (–) cable at battery.
2) Remove radiator and condenser cooling fan relay No.1 (1),
No.2 (2) and No.3 (3) from vehicle.
3) Check that there is no continuity between terminal “c” and
“b”. If there is continuity, replace relay.
4) Connect battery positive (+) terminal to terminal “b” of relay.
Connect battery negative (–) terminal “a” of relay.
Check continuity between terminal “c” and “d”.
If there is no continuity when relay is connected to the bat-
tery, replace relay.
WATER PUMP/GENERATOR DRIVE BELT
REMOVAL
1) Disconnect negative cable at battery.
2) Loosen drive belt adjusting bolt (2) and generator pivot bolt
(3).
When servicing car equipped with A/C, remove compressor
drive belt (4) before removing water pump belt (1).
Refer to “COMPRESSOR DRIVE BELT” in Section 1B.
3) Slacken belt by displacing generator and then remove it.
ba
1
c
dc
ad
b
2
3
1
c
d
2, 3b a
ac
d
b
2
3
1
4
6E1-2 ENGINE AND EMISSION CONTROL SYSTEM
CRANKSHAFT POSITION SENSOR .. 6E1-32
VEHICLE SPEED SENSOR (VSS) ...... 6E1-33
FUEL LEVEL SENSOR (GAUGE) ....... 6E1-33
KNOCK SENSOR (IF EQUIPPED) ...... 6E1-33
MAIN RELAY, FUEL PUMP RELAY
AND RADIATOR FAN RELAY NO.1.... 6E1-33
FUEL CUT OPERATION ..................... 6E1-34
RADIATOR FAN CONTROL
SYSTEM .............................................. 6E1-34
RADIATOR FAN RELAY NO. 2 AND
NO.3 ..................................................... 6E1-34OUTPUT SIGNALS OF THROTTLE
VALVE OPENING AND ENGINE
COOLANT TEMP. (VEHICLE WITH
A/T ONLY) ........................................... 6E1-36
EMISSION CONTROL SYSTEM ............. 6E1-36
EGR SYSTEM ..................................... 6E1-36
EVAPORATIVE EMISSION CONTROL
SYSTEM .............................................. 6E1-37
PCV SYSTEM ...................................... 6E1-39
SPECIAL TOOL .......................................... 6E1-40
TIGHTENING TORQUE SPECIFICATION . 6E1-41
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.
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