Downloaded from www.Manualslib.com manuals search engine 3D-2 FRONT SUSPENSION
General Description
4WD Control System
The 4WD control system consists of a 4WD switch, a vacuum switch, a vacuum tank, two vacuum switching
valves (VSV1 and VSV2) and air locking hub assemblies.
The 4WD controller controls locking or unlocking of the air locking hub according to operation of the transfer shift
control lever.
Vacuum generated in the intake manifold passes through the check valve and stored in the vacuum tank.
According to signals from the 4WD switch, the 4WD controller activates VSV1 (for unlocking) or VSV2 (for lock-
ing) to apply vacuum from the vacuum tank so that the front axle and the wheel hub are disengaged or engaged.
1. Front axle housing 3. Steering knuckle 5. Wheel spindle 7. Wheel bearing
2. Shock absorber 4. Kingpin 6. Wheel hub 8. Front axle shaft (4WD)
Downloaded from www.Manualslib.com manuals search engine FRONT SUSPENSION 3D-3
1. Air locking hub assembly 4. VSV2 7. 4WD controller 10. 4WD indicator light 13. ABS controller
2. VSV1 5. Vacuum accumulation tank 8. Intake manifold 11. 4WD switch 14. Transfer
3. Check valve 6. Vacuum switch 9. Wheel spindle 12. Combination meter
Downloaded from www.Manualslib.com manuals search engine FRONT SUSPENSION 3D-5
Components and Functions
Component Function
4WD switch When the transfer shift lever is shifted to 4L or 4H position from 2H, this switch
turns ON and cause the 4WD control system to turn ON.
4WD controller When the 4WD switch turns on, the 4WD controller activates VSV2 to lock the
air locking hubs and when it receives an “ON” signal from the vacuum switch, it
makes VSV2 to complete operation within 5 seconds and causes the 4WD indi-
cator light to light up.
If vacuum in the vacuum circuit fails to reach the specified level due to a leakage
in the vacuum circuit (when no “ON” signal is inputted from the vacuum switch),
the 4WD controller stops operation of VSV2 in 15 seconds and makes the 4WD
indicator light to flash to warn occurrence of a trouble.
When the 4WD switch turns off, the 4WD controller activates VSV1 for 10 sec-
onds to unlock the hubs and at the same time makes the 4WD indicator light
turn off.
VSV1 VSV1 operates according to the signal from the 4WD controller. When it is acti-
vated, the port opens and vacuum in the intake manifold is applied through the
vacuum circuit to unlock to the slide gear in the air locking hub. As a result, the
air locking hubs are unlocked.
VSV2 VSV2 operates according to the signal from the 4WD controller. When it is acti-
vated, the port opens and vacuum in the intake manifold is applied through the
vacuum circuit to lock to the slide gear in the air locking hub. As a result, the air
locking hubs are locked.
Vacuum switch When VSV2 receives the “ON” signal from 4WD switch, vacuum is applied
through its circuit to the vacuum switch. The vacuum switch turns on when it
detects vacuum exceeding 260 mmHg.
“4WD” indicator lamp It lights up when 4WD control system is in the 4WD mode.
It flashes to warn that locking hub operation has not completed (4WD control
system fails to shift 4WD).
Downloaded from www.Manualslib.com manuals search engine 3D-6 FRONT SUSPENSION
OPERATION
2WD
→ 4WD
When the transfer shift control lever is shifted from the 2WD (2H) position to the 4WD (4H or 4L) position, a 4WD
“ON” signal is transmitted to the 4WD controller which then activates VSV2 to apply vacuum in the intake mani-
fold to the chamber “B” in the hub housing.
When vacuum is applied, the slide gear is separated from the magnet, moves toward the center of the vehicle
body and gets engaged with the outer gear. In this way, the front axle shaft and the front wheel hub rotate as one
unit.
If vacuum in the circuit fails to reach 260 mmHg within 15 seconds after operation of VSV2 due to such trouble
as a hole in the vacuum pipe, the slide gear does not operate and the 4WD indicator light flashes to warn that
the hub is unlocked.
1. ECM 8. Engine speed signal 15. Chamber B 22. Slide gear
2. 4WD controller 9. Intake manifold 16. Piston A 23. Wheel hub
3. 4WD indicator lamp 10. Check valve 17. Magnet 24. Spindle
4.4WD switch 11. Vacuum tank 18. Housing 25. Front axle shaft
5. A/C switch (if equipped) 12. VSV1 19. Spring 26. To opposite side
6. Vacuum switch 13. VSV2 20. Diaphragm 27. A/C controller
7. A/C cut signal (if equipped) 14. Outer gear 21. Sleeve A: Vacuum circuit
Downloaded from www.Manualslib.com manuals search engine FRONT SUSPENSION 3D-7
4WD
→ 2WD
When the transfer shift control lever is shifted from the 4WD (4H or 4L) to the 2WD (2H) position, the 4WD con-
troller activates VSV1 and the intake manifold vacuum is applied to the chamber “A” in the hub housing. As the
slide gear is shifted to the wheel side by the vacuum force and disengaged from the outer gear, rotation of the
front wheel hub is not transmitted to the front axle shaft.
1. EPI & A/C controller 8. Engine speed signal 15. Chamber A 22. Slide gear
2. 4WD controller 9. Intake manifold 16. Piston A 23. Wheel hub
3. 4WD indicator lamp 10. Check valve 17. Magnet 24. Spindle
4.4WD switch 11. Vacuum tank 18. Housing 25. Front axle shaft
5. A/C switch (if equipped) 12. VSV1 19. Spring 26. To opposite side
6. Vacuum switch 13. VSV2 20. Diaphragm 27. A/C controller
7. A/C cut signal (if equipped) 14. Outer gear 21. Sleeve A: Vacuum circuit
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CHECK VALVE
1) Remove check valve (1).
2) Close B side of check valve with finger as shown and apply
–50 cmHg vacuum by means of vacuum pump. Then check
that vacuum is applied. Apply vacuum to another side of
check valve and check that vacuum is not applied.
Replace if defective.
Special tool
(A) : 09917-47910
Stabilizer bar / bushing check
BAR
Inspect for damage or deformation. If defective, replace.
BUSHING
Inspect for damage, wear or deterioration. If defective, replace.
A : Intake manifold side
B : Vacuum switching valve side
Downloaded from www.Manualslib.com manuals search engine 6-2 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Diagnostic trouble code (DTC) table ......... 6-16
Fail-safe table............................................ 6-19
Visual inspection ....................................... 6-20
Engine basic inspection ............................ 6-21
Engine diagnosis table .............................. 6-23
Scan Tool Data ............................................. 6-28
Scan tool data definitions .......................... 6-30
Inspection of ECM and Its Circuits ................ 6-33
Component Location ..................................... 6-42
Table A-1 Malfunction Indicator Lamp Circuit
Check - Lamp Does Not Come “ON” at Ignition
Switch ON (But Engine at Stop).................... 6-43
Table A-2 Malfunction Indicator Lamp Circuit
Check - Lamp Remains “ON” after Engine
Starts............................................................. 6-44
Table A-3 Malfunction Indicator Lamp Circuit
Check - Mil Flashes at Ignition Switch ON .... 6-45
Table A-4 Malfunction Indicator Lamp Circuit
Check - MIL Does Not Flash, Just Remains
ON or Just Remains OFF Even with Grounding
Diagnosis Switch Terminal............................ 6-45
Table A-5 ECM Power and Ground Circuit
Check - MIL Doesn’t Light at Ignition Switch
ON and Engine Doesn’t Start Though It Is
Cranked Up ................................................... 6-46
DTC P0105 (DTC No.11) Manifold Absolute
Pressure (MAP) Circuit Malfunction .............. 6-48
DTC P0110 (DTC No.18) Intake Air Temp.
(IAT) Circuit Malfunction ............................... 6-51
DTC P0115 (DTC No.19) Engine Coolant
Temperature (ECT) Circuit Malfunction ........ 6-53
DTC P0120 (DTC No.13) Throttle Position
Circuit Malfunction ........................................ 6-55
DTC P0121 Throttle Position Circuit Range /
Performance Problem ................................... 6-57
DTC P0130 (DTC No.14) Heated Oxygen
Sensor (HO2S) Circuit Malfunction
(Sensor-1) ..................................................... 6-59
DTC P0133 Heated Oxygen Sensor (HO2S)
Circuit Slow Response (Sensor-1) ................ 6-61
DTC P0135 (DTC No.14) Heated Oxygen
Sensor (HO2S) Heater Circuit Malfunction
(Sensor-1) ..................................................... 6-62
DTC P0136 Heated Oxygen Sensor (HO2S)
Circuit Malfunction (Sensor-2) ...................... 6-64
DTC P0141 Heated Oxygen Sensor (HO2S)
Heater Circuit Malfunction (Sensor-2)........... 6-66
DTC P0171 Fuel System Too Lean .............. 6-68
DTC P0172 Fuel System Too Rich ............... 6-68
DTC P0300 Random Misfire Detected
(Misfire Detected at 2 or More Cylinders) ..... 6-72DTC P0301 Cylinder 1 Misfire Detected ........ 6-72
DTC P0302 Cylinder 2 Misfire Detected ........ 6-72
DTC P0303 Cylinder 3 Misfire Detected ........ 6-72
DTC P0304 Cylinder 4 Misfire Detected ........ 6-72
DTC P0325 (DTC No.17) Knock Sensor Circuit
Malfunction .................................................... 6-77
DTC P0335 (DTC No.23) Crankshaft Position
(CKP) Sensor Circuit Malfunction .................. 6-79
DTC P0340 (DTC No.15) Camshaft Position
(CMP) Sensor Circuit Malfunction ................. 6-82
DTC P0400 Exhaust Gas Recirculation Flow
Malfunction .................................................... 6-85
DTC P0420 Catalyst System Efficiency below
Threshold ....................................................... 6-88
DTC P0443 Purge Control Valve Circuit
Malfunction .................................................... 6-91
DTC P0481 A/C Condenser Fan Control
Circuit Malfunction ......................................... 6-92
DTC P0500 (DTC No.16) Vehicle Speed
Sensor (VSS) Malfunction ............................. 6-94
DTC P0505 Idle Control System
Malfunction .................................................... 6-96
DTC P0601 Internal Control Module Memory
Check Sum Error (DTC No.71) ...................... 6-98
DTC P1450 Barometric Pressure Sensor
Low / High Input ............................................. 6-99
DTC P1451 Barometric Pressure Sensor
Performance Problem .................................... 6-99
DTC P1500 Engine Starter Signal Circuit
Malfunction .................................................. 6-101
DTC P1510 ECM Back-up Power Supply
Malfunction .................................................. 6-103
DTC P1570 (DTC No.21) ABS Signal Circuit
Malfunction .................................................. 6-104
DTC P1600 Serial Communication Problem
Between ECM and TCM .............................. 6-105
DTC P1717 A/T Drive Range (Park / Neutral
Position) Signal Circuit Malfunction ............. 6-107
Table B-1 Fuel Injector Circuit Check ..........6-109
Table B-2 Fuel Pump and Its Circuit
Check........................................................... 6-110
Table B-3 Fuel Pressure Check................... 6-112
Table B-4 Idle Air Control System Check ....6-114
Table B-5 A/C Signal Circuits Check
(Vehicle with A/C) ........................................ 6-117
Table B-6 Electric Load Signal Circuit
Check........................................................... 6-119
TAble B-7 A/C Condenser Fan Control
System Check.............................................. 6-121
Special Tool ................................................... 6-123
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-3
General Information
Statement on Cleanliness and Care
An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances
that are measured in the thousands of an millimeter (ten thousands of an inch).
Accordingly, when any internal engine parts are serviced, care and cleanliness are important.
Throughout this section, it should be understood that proper cleaning and protection of machined surfaces and
friction areas is part of the repair procedure. This is considered standard shop practice even if not specifically
stated.
A liberal coating of engine oil should be applied to friction areas during assembly to protect and lubricate the
surfaces on initial operation.
Whenever valve train components, pistons, piston rings, connecting rods, rod bearings, and crankshaft jour-
nal bearings are removed for service, they should be retained in order.
At the time of installation, they should be installed in the same locations and with the same mating surfaces
as when removed.
Battery cables should be disconnected before any major work is performed on the engine.
Failure to disconnect cables may result in damage to wire harness or other electrical parts.
Throughout this manual, the four cylinders of the engine are
identified by numbers; No.1 (1), No.2 (2), No.3 (3) and No.4
(4) counted from crankshaft pulley side to flywheel side.
General Information on Engine Service
THE FOLLOWING INFORMATION ON ENGINE SERVICE SHOULD BE NOTED CAREFULLY, AS IT IS
IMPORTANT IN PREVENTING DAMAGE, AND IN CONTRIBUTING TO RELIABLE ENGINE PERFORMANCE.
When raising or supporting engine for any reason, do not use a jack under oil pan. Due to small clearance
between oil pan and oil pump strainer, jacking against oil pan may cause it to be bent against strainer result-
ing in damaged oil pick-up unit.
It should be kept in mind, while working on engine, that 12-volt electrical system is capable of violent and
damaging short circuits.
When performing any work where electrical terminals can be grounded, ground cable of the battery should
be disconnected at battery.
Any time the air cleaner, throttle body or intake manifold is removed, the intake opening should be covered.
This will protect against accidental entrance of foreign material which could follow intake passage into cylin-
der and cause extensive damage when engine is started.