PS-49
General Diagnostic Table
POWER ASSISTED SYSTEM (POWER STEERING)
10.General Diagnostic Table
A: INSPECTION
*1 If the tires or wheels are wider than standard, the load to the power steering system is increased. Accordingly, in a condition,
for example before fluid warms-up, relief valve may work before reaching maximum turning angle. In this case, steering effort
may be heavy. When the measured hydraulic pressure is normal, there is no abnormal thing. *2 In cold weather, flow resistance will increase due to the cold hydraulic fluid, and steering effort will be heavier. After warming-up en-
gine, turn the steering wheel from stop to stop several times to warm-up fluid. If steering effort reduces normally, function is normal. *3 I n c o l d w e a t h e r o r w i t h i n s u f f i c i e n t w a r m – u p o f t h e e n g i n e , s t e e r i n g e f f o r t m a y b e h e a v y d u e t o e x c e s s i v e d r o p o f i d l e r p m w h en
turning the steering wheel. In this case, start the vehicle with increasing engine speed than usual. If steering effort reduces nor-
mally, function is normal.
Tr o u b l e P o s s i b l e c a u s e C o r r e c t i v e a c t i o n
•Steering effort is heavy in all
ranges.
•Steering effort is heavy at
stand still.
•Steering wheel vibrates
when turning.
1. Pulley belt
•Unequal length of pulley belts
•Contact with oil or grease
•Looseness or damage of the pulley belt
•Poor uniformity of the pulley belt cross section
•Pulley belt touches to pulley bottom
•Poor revolution of pulleys (except oil pump pulley)
•Poor revolution of oil pump pulley
Adjust or replace.
2. Tire and wheel
•Improper tire out of specifications*1
•Improper wheel out of specifications*1
•Tires not properly inflated
Replace or reinflate.
3. Fluid
•Low fluid level
•Air entry in fluid
•Entry of dust in the fluid
•Fluid deterioration
•Inadequate warm–up of fluid *2
Refill, bleed air,
replace or instruct cus-
tomer.
4. Idle speed
•Lower idle speed
•Excessive drop of idle speed at start or when turning the steering
wheel *3
Adjust or instruct cus-
tomer.
5. Measure the hydraulic pressure.
Replace the problem
parts.
6. Measure the steering wheel effort.
•Vehicle leads to one side or
the other.
•Returning force of steering
wheel to center is poor.
•Steering wheel vibrates
when turning.
1. Fluid line
•Folded hose
•Flattened pipe
Correct or replace.
2. Tire and wheel
•Flat tire
•Mixed use of different tires
•Mixed use of different wheels
•Abnormal wear of tire
•Unequal tread remaining
•Unequal pressure of tire
Adjust, fix or replace.
3. Front alignment
•Improper or unequal caster
•Improper or unequal toe–in
•Loose suspension connections
Adjust or retighten.
4. Others
•Damaged joint assembly
•Unbalanced height
•Unbalanced weight
Replace, adjust or
instruct customer.
5. Measure the steering wheel effort.
PS-50
General Diagnostic Table
POWER ASSISTED SYSTEM (POWER STEERING)
1. NOISE & VIBRATION
CAUTION:
Do not keep the relief valve operated over five seconds at any time or inner parts of the oil pump may
be damaged due to rapid increase of fluid temperature.
NOTE:
•A screeching noise may be heard immediately after the engine start in extremely cold conditions. In this
case, if the noise goes off during warm-up there is no abnormal function in the system. This is due to the fluid
characteristics in extremely cold condition.
•The oil pump normally makes a small whining noise due to its mechanism. Even if a noise is heard when
steering wheel is turned at stand still, there is no abnormal function in the system provided that the noise
eliminates when the vehicle is driving.
•When turning the steering wheel with the brake applied when the vehicle is parked, a screeching noise
may be generated by the brake disc and pads. This is not a fault in the steering system.
•There may be a small vibration around the steering devices when turning the steering wheel at standstill,
even though the component parts are operating properly.
Hydraulic systems are likely to generate this kind of vibration as well as working noise and fluid noise be-
cause of combined conditions, i.e., road surface and tire surface, engine speed and turning speed of steering
wheel, fluid temperature and braking condition.
These conditions do not indicate a problem in the system.
Confirm vibration for an AT model, by applying the parking brake on a concrete surface, shifting into the “D”
range, and turning the steering wheel repeatedly from slow to rapid, step by step.
Tr o u b l e P o s s i b l e c a u s e C o r r e c t i v e a c t i o n
Hiss noise (continuous)
While engine is running.
Relief valve emits operating sound when steering wheel is
completely turned in either direction. (Do not keep this
condition over five seconds.)
Normal
Relief valve emits operating sound when steering wheel is
not turned. This means that the relief valve is defective. Replace the oil pump.
Rattling noise (intermittent)
While engine is running.
Interference with adjacent parts
Check the clearance.
Correct if necessary.
Loosened installation of oil pump, oil tank, pump bracket,
gearbox or crossmemberRetighten.
Loose oil pump pulley or other pulley(s) Retighten.
Looseness of linkage, play of steering, improper tightening
(looseness) of suspension joint or steering columnRetighten or replace.
Sound generates from the inside of gearbox or oil pump.Replace faulty parts in the gear-
box or oil pump.
Knocking
When turning steering wheel in
both directions with small angle
repeatedly at engine ON or OFF.
Excessive backlash
Loosened lock nut for adjusting backlashAdjust and retighten.
Insufficient tightening or play in the tie–rod or tie–rod end Retighten or replace.
Grinding noise (continuous)
While engine is running.
Air in vane pump
Inspect and retighten the fluid
line connection.
Refill the fluid and vent air.
Va n e p u m p s e i z i n g R e p l a c e t h e o i l p u m p.
Oil pump pulley bearing seized Replace the oil pump.
Folded hose, flattened pipe Replace.
Squeal, squeak (intermittent or
continuous)
While engine is running.
Improper adjustment of pulley belt
Damaged or over tensioned pulley belt
Unequal length of pulley belts
Adjust or replace.
(Replace two belts as a set.)
Runout or dirty V–groove surface of oil pump pulley Clean or replace.
PS-51
General Diagnostic Table
POWER ASSISTED SYSTEM (POWER STEERING)
Sizzling noise (continuous)
While engine is running.
Fluid aeration
Fix the faulty part causing aera-
tion.
Replace the fluid and vent air.
Damaged pipe of gearbox Replace the pipe.
Fa u lt y i n si de of h os e o r pi p e
Flattened hose or pipeRepair or replace.
Abnormal inside of oil tank Replace.
Removed oil tank cap Install cap.
Whistle (continuous)
While engine is running.Fa u lt y p i pe of g ea r b ox o r fa ul t y h os eReplace the faulty parts of the
gearbox or the hose.
Whine or growl (intermittent or
continuous)
While engine is running with/
without steering turned.
Looseness of oil pump, oil pump bracket attachment Retighten.
Fa u lt in s id e o f oi l p u mp o r h os e
Replace the oil pump or hose, if
the noise can be heard when
vehicle is running as well as
being stopped.
To r q u e c o n v e r t e r g r o w l , a i r c o n d i t i o n e r c o m p r e s s i o n g r o w lRemove the power steering pul-
ley belt and check.
Grinding noise (continuous)
While engine is running with the
steering turned.
Fa u lt in s id e o f ge a rb oxReplace the faulty parts of gear-
box.
Fa u lt y s t ee r i ng sh af t b ea r i ng A pp l y gr ea s e o r r e p la ce.
Occurs when turning the steering wheel with brakes (ser-
vice or parking) applied.
If the noise goes off when brake
is released, it is normal.
Vibration
While engine is running with/
without steering turned.
Engine speed is too low. Adjust, and notify customer.
Air in vane pumpRepair faulty part
Ve n t a i r.
Damaged valve in oil pump or gearboxReplace the faulty parts in gear-
box and oil pump.
Excessive play in steering, looseness of suspension parts Retighten.
Tr o u b l e P o s s i b l e c a u s e C o r r e c t i v e a c t i o n
PS-52
General Diagnostic Table
POWER ASSISTED SYSTEM (POWER STEERING)
2. MEASUREMENT OF STEERING EFFORT
Step Check Yes No
1CHECK STEERING EFFORT.
1) Stop the vehicle on paved road.
2) Start the engine.
3) Run the engine at idle.
4) Install a spring scale on the steering wheel.
5) Pull the spring scale at a right angle to the
steering wheel, and measure both right and left
steering wheel efforts.
NOTE:When turning the steering more quickly than
necessary from a direction to the other direction
at an engine speed over 2,000 rpm, steering ef-
fort may be heavy. This is caused by flow char-
acteristic of the fluid in the oil pump and is not a
defect.
Is the steering effort less than
29.4 N (3.0 kgf, 6.6 lb)?
Go to step 2.Adjust the back-
lash.
2CHECK STEERING EFFORT.
1) Stop the engine.
2) Pull the spring scale at a right angle to the
steering wheel, and measure both right and left
steering wheel efforts.
Is the steering effort less than
294.2 N (30 kgf, 66.2 lb)?
Go to step 3.Perform the
adjustment.
3CHECK STEERING WHEEL EFFORT.
1) Remove the universal joint.
2) Measure the steering wheel effort.
Is steering effort less than 2.26
N (0.23 kgf, 0.51 lb)?
Go to step 4.Check, adjust and
replace if neces-
sary.
4CHECK STEERING WHEEL EFFORT.
Measure the steering wheel effort.
Is the difference of steering
effort between right and left
less than 20%?
Go to step 5.Check, adjust and
replace if neces-
sary.
5CHECK UNIVERSAL JOINT.
Measure the swing torque of the joint (yoke of
steering column side).
Is the swing torque of the uni-
versal joint less than 7.3 N
(0.74 kgf, 1.64 lb)?
Go to step 6.Replace with a
new part.
6CHECK UNIVERSAL JOINT.
Measure the swing torque of the joint (yoke of
gearbox side).
Is the swing torque of the uni-
versal joint less than 3.8 N
(0.39 kgf, 0.86 lb)?
Go to step 7.Replace with a
new part.
7CHECK FRONT WHEEL.
Check the front wheels.
Does the front wheels have
unsteady revolution or rattling,
or does the brake drag?
Inspect, readjust
and replace if nec-
essary.
Go to step 8.
8CHECK TIE–ROD ENDS.
Remove the tie–rod ends.
If the tie-rod ends of suspen-
sion have unsteady revolution
or rattling?
Inspect and
replace if neces-
sary.
Go to step 9.
9BALL JOINT CHECK.
Remove the ball joint.
If the ball joints of suspension
have unsteady revolution or
rattling?
Inspect and
replace if neces-
sary.
Go to step 10.
10 CHECK GEARBOX.
Measure the rotating of gearbox.
box.>
Is the rotating resistance of
steering gearbox less than
10.5 N (1.1 kgf, 2.4 lb)? Is the
difference between right and
left sides less than 20%?
Go to step 11.Readjust the back-
lash, and if ineffec-
tive, replace the
faulty par ts.
11 CHECK GEARBOX.
Measure the sliding of gearbox.
Is the sliding resistance of
steering gearbox less than 400
N (41 kgf, 90 lb)? Is the differ-
ence between the right and left
sliding resistance less than
20%?
Steering effort is
normal.
Readjust the back-
lash, and if ineffec-
tive, replace the
faulty par ts.
CO(H6DO)-8
Radiator Fan System
COOLING
B: RADIATOR FAN CONTROL OUTPUT WAVEFORM
C: INSPECTION
DETECTING CONDITION:
•Engine coolant temperature is more than 95°C (203°F).
•A/C switch is turned OFF.
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOMS:
Radiator main fan and sub fan do not rotate under the above conditions.
(A) 5 V
Step Check Yes No
1CHECK MAIN FAN RELAY 1.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay 1 from A/C relay
holder.
3) Measure the resistance of terminal in main
fan relay 1 switch.
Is the resistance more than 1
MΩ?
Go to step 2.Replace the main
fan relay 1.
2CHECK MAIN FAN RELAY 1.
1) Connect the battery to terminal of main fan
relay 1 coil.
2) Measure the resistance between terminals
of main fan relay 1 switch.
Is the resistance less than 1
Ω?
Go to step 3.Replace the main
fan relay 1.
3CHECK POWER SUPPLY FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM.
3) Turn the ignition switch ON.
4) Measure the voltage between ECM termi-
nal and chassis ground.
Connector & terminal
(B136) No. 29 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 4.Repair the power
supply line.
CO-02117
(V)
0
(A)
CO(H6DO)-14
Thermostat
COOLING
5. Thermostat
A: REMOVAL
1) Set the vehicle on a lift.
2) Lift-up the vehicle.
3) Remove the under cover.
4) Drain engine coolant completely.
5) Disconnect the radiator hose from thermostat
cover.
6) Remove the thermostat cover, and then remove
the thermostat.
B: INSTALLATION
1) Install a gasket to thermostat.
NOTE:
Use a new gasket.
2) Install the thermostat and thermostat cover.
NOTE:
The thermostat must be installed with the jiggle pin
facing to the up side.
Tightening torque:
6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
3) Connect the radiator hose to thermostat cover.
4) Install the under cover.
5) Lower the vehicle.
6) Fill engine coolant.
MENT, Engine Coolant.>
C: INSPECTION
Replace the thermostat if the valve does not close
completely at an ambient temperature or if the fol-
lowing test shows unsatisfactory results.
•Inspection method
Immerse the thermostat and a thermometer in wa-
ter. Raise water temperature gradually, and mea-
sure the temperature and valve lift when the valve
begins to open and when the valve is fully opened.
During the test, agitate the water for even temper-
ature distribution. The measured value should
meet the specification.
Starting temperature to open:
80 — 84°C (176 — 183°F)
Fully opens:
95°C (203°F)
NOTE:
•Leave the thermostat in the boiling water for
more than five minutes before measuring the
valve lift.
•Hold the thermostat with a wire or the like to
avoid contacting with container bottom.
Valve lift:
9.0 mm (0.354 in) or more
CO-02015
CO-02016
CO-02016
(A) Thermometer
(B) Thermostat
CO-00033
(A)
(B)
CO(H6DO)-30
Engine Cooling System Trouble in General
COOLING
12.Engine Cooling System Trouble in General
A: INSPECTION
Tr o u b l e P o s s i b l e c a u s e C o r r e c t i v e a c t i o n
Overheating
a. Insufficient engine coolantReplenish engine coolant, inspect for leakage, and
repair it if necessary.
b. De fe c ti ve t he r mo st a t Rep la c e.
c. Malfunction of water pump Replace.
d. Clogged engine coolant passage Clean.
e. Improper ignition timing
Inspect and repair ignition control system.
Procedure.>
f. Clogged or leaking radiator Clean, repair or replace.
g. Improper engine oil in engine coolant Replace engine coolant.
h. Air/fuel mixture ratio too lean
Inspect and repair the fuel injection system.
Procedure.>
i. Excessive back pressure in exhaust system Clean or replace.
j. Insufficient clearance between piston and cylinder Adjust or replace.
k. Slipping clutch Correct or replace.
l. Dragging brake Adjust.
m. Faulty transmission gear oil Replace.
n. Malfunction of radiator fanInspect the radiator fan relay, engine coolant tempera-
ture sensor or fan motor and replace them.
Over-coolinga. Ambient temperature extremely low Partly cover radiator front area.
b. De fe c ti ve t he r mo st a t Rep la c e.
Engine coolant
leaks
a. Loosened or damaged connecting units on hoses Correct or replace.
b. L ea k ag e f r o m wat e r pu mp Rep la c e.
c. Leakage from water pipe Correct or replace.
d. Leakage around cylinder head gasket Retighten cylinder head bolts or replace gasket.
e. Damaged or cracked cylinder head and crankcase Correct or replace.
f. Damaged or cracked ther mostat case Correct or replace.
g. Leakage from radiator Correct or replace.
Strange noise
a. Defective drive belt Replace.
b. De fe c ti ve ra di a t or fan Rep la c e.
c. Defective water pump bearing Replace water pump.
d. Defective water pump mechanical seal Replace water pump.
EN(H6DO)(diag)-4
Check List for Interview
ENGINE (DIAGNOSTICS)
2. CHECK LIST No. 2
Check the following item about the vehicle's state when malfunction indicator light turns on.
NOTE:
Use copies of this page for interviewing customers.
a) Other warning lights or indicators turn on. Yes/ No
Low fuel warning light
Charge indicator light
AT diagnostic indicator light
ABS warning light
Oil pressure indicator light
b) Fuel level
•Lack of gasoline: Yes/ No
•Indicator position of fuel gauge:
•Experienced running out of fuel: Yes/ No
c) Intentional connecting or disconnecting of harness connectors or spark plug cords: Yes/ No
•What:
d) Intentional connecting or disconnecting of hoses: Yes/ No
•What:
e) Installing of parts other than genuine parts: Yes/ No
•What:
•Where:
f) Occurrence of noise: Yes/ No
•From where:
•What kind:
g) Occurrence of smell: Yes/ No
•From where:
•What kind:
h) Intrusion of water into engine compartment or passenger compartment: Yes/ No
i) Troubles occurred
Engine does not start.
Engine stalls during idling.
Engine stalls while driving.
Engine speed decreases.
Engine speed does not decrease.
Rough idling
Poor acceleration
Back fire
After fire
No shift
Excessive shift shock