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.
VDC-5
General Description
VEHICLE DYNAMICS CONTROL (VDC)
5. RELAY BOX
C: CAUTION
Please clearly understand and adhere to the follow-
ing general precautions. They must be strictly fol-
lowed to avoid any injury to the person doing the
work or people in the area.
1. OPERATION
•Wear work clothing, including a cap, protective
goggles and protective shoes during operation.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust and dirt.
•Before disconnecting connectors of sensors or
units, be sure to disconnect the ground cable from
the battery.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly and replacement.
•Be careful not to burn yourself, because each
part on the vehicle is hot after running.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Place shop jacks or rigid racks at the specified
points.
2. OIL
When handling oil, follow the rules below to prevent
unexpected accidents.
•Prepare container and waste cloths when per-
forming work which oil could possibly spill. If oil
spills, wipe it off immediately to prevent from pene-
trating into floor or flowing outside, for environmen-
tal protection.
•Follow all government and local regulations con-
cerning waste disposal.
3. BRAKE FLUID
If brake fluid gets in your eyes or on your skin, do
the following:
•Wash eyes and seek immediate medical atten-
tion.
•Wash your skin with soap and then rinse thor-
oughly with water.
Follow all government and local regulations con-
cerning waste disposal.
(1) Relay box (4) Fuel safe relay (green)Tightening torque: N·m (kgf-m, ft-lb)
(2) Cover (5) Vacuum pump relay (black)T: 18 (1.8, 13.0)
(3) Motor relay (blue)
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)-18
Engine Control Module (ECM) I/O Signal
ENGINE (DIAGNOSTICS)
Manifold absolute pressure sen-
sorB134 6 3.5 — 4.8 1.1 — 1.9 —
Air flow sensor
Signal B135 26 0.74 0.3 — 4.5 —
Shield B135 35 0 0 —
Ground B135 34 0 0 —
Intake air temperature sensor B135 18 3.15 — 3.33 3.15 — 3.33Intake air tempera-
ture 25°C (75°F)
Fr o nt ox yg e n ( A / F)
sensor RH
Signal (+) B135 9 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 8 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater RH
Signal 1 B136 3 12 — 14 — Waveform
Signal 2 B136 2 12 — 14 — Waveform
Fr o nt ox yg e n ( A / F)
sensor LH
Signal (+) B135 11 2.8 — 3.2 2.8 — 3.2 —
Signal (–) B135 10 2.4 — 2.7 2.4 — 2.7 —
Shield B135 1 0 0 —
Fr o nt ox yg e n ( A / F)
sensor heater LH
Signal 1 B135 7 12 — 14 — Waveform
Signal 2 B135 6 12 — 14 — Waveform
Rear oxygen sen-
sor RH
Signal B135 4 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater RH
signalB136 4 12 — 14 — Waveform
Rear oxygen sen-
sor LH
Signal B135 15 0 0 — 0.9 —
Shield B135 1 0 0 —
Rear oxygen sensor heater LH
signalB136 5 12 — 14 — Waveform
Immobilizer communication 1 B136 26 10 10 —
Immobilizer communication 2 B136 34 10 10 —
Fuel pump control
unit
Diagnosis
signalB135 33 10 — 13 13 — 14 —
Control B136 12 0 0 or 5 —
Brake switch 1 B135 20
When brake pedal is
depressed: 0
When brake pedal is
released: 10 — 13
When brake pedal is
depressed: 0
When brake pedal is
released: 13 — 14
—
Brake switch 2 B135 28
When brake pedal is
depressed: 10 — 13
When brake pedal is
released: 0
When brake pedal is
depressed: 13 — 14
When brake pedal is
released: 0
—
Cruise control command switch B135 24
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
When operating
nothing: 3.5 — 4.5
When operating
RES/ACC: 2.5 — 3.5
When operating SET/
COAST: 0.5 — 1.5
When operating
CANCEL: 0 — 0.5
—
Cruise control main switch B135 12ON: 0
OFF: 5
ON: 0
OFF: 5—
Oil flow control sole-
noid valve RH
Signal (+) B137 17 0 0.6 —
Signal (–) B137 16 0 0 —
Oil flow control sole-
noid valve LH
Signal (+) B137 15 0 0.6 —
Signal (–) B137 14 0 0 —
DescriptionConnector
No.
Te r m i n a l
No.
Signal (V)
ReferenceIgnition SW ON
(engine OFF)
Engine ON
(idling)
EN(H6DO)(diag)-27
Subaru Select Monitor
ENGINE (DIAGNOSTICS)
4. READ CURRENT DATA FOR ENGINE (NORMAL MODE)
1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen, select the {Engine} and press the [YES] key.
3) Press the [YES] key after the information of engine type has been displayed.
4) On the «Engine Diagnosis» display screen, select the {Current Data Display/Save}, and then press the
[YES] key.
5) On the «Data Display Menu» screen, select the {Data Display} and press the [YES] key.
6) Using the scroll key, scroll the display screen up or down until the desired data is shown.
•A list of the support data is shown in the following table.
Description Display Unit of measure Note (at idling)
Engine load Engine load % 3.5%
Engine coolant temperature signal Coolant Temp. °C or °F≥ 75°C or 167°F (After
engine is warmed-up.)
A/F compensation 1 A/F Compensation 1 % 3.1%
A/F learning 1 A/F learning 1 % 0.0%
A/F compensation 2 A/F Compensation 2 % 4.7%
A/F learning 2 A/F learning 2 % 0.0%
Intake manifold absolute pressure Mani. Absolute PressuremmHg, kPa,
inHg or psig
200 — 300 mmHg, 26.7 —
40 kPa, 7.8 — 11.8 inHg or
3.8 — 5.8 psig
Engine speed signal Engine speed rpm 600 — 800 rpm
Meter vehicle speed signal Meter vehicle speed km/h or MPH 0 km/h or 0 MPH
Ignition timing signal Ignition timing deg 13 — 15 deg
Intake air temperature signal Intake air temperature °C or °F (Ambient air temperature)
Amount of intake air Mass Air Flow g/s or lb/m 3.8 g/s or 0.5 lb/m
Throttle opening angle signal Throttle valve angle % 1.2 — 1.6%
Fr o nt ox yg e n se n so r vo lt a g e val ue 1Fr o n t oxy ge n s en s or vol t ag e
value 1V0.035 V
Fr o nt ox yg e n se n so r vo lt a g e val ue 2Fr o n t oxy ge n s en s or vol t ag e
value 2V0.020 V
Battery voltage Battery Voltage V 12 — 14 V
Mass air flow voltage Mass air flow voltage V 1.1 — 1.2 V
Injection 1 pulse width Injection 1 pulse width ms 2.82 ms
Injection 2 pulse width Injection 2 pulse width ms 2.82 ms
Knock sensor compensation Knock correction deg 0 deg
Atmospheric pressure signal Atmospheric pressuremmHg, kPa,
inHg or psig(Atmospheric pressure)
Intake manifold relative pressureIntake manifold relative pres-
sure
mmHg, kPa,
inHg or psig
(Intake manifold absolute
pressure — atmospheric
pressure)
Acceleration opening angle signal Acceleration opening angle % 0%
Radiator fan output Radiator fan output % 0%
Purge control solenoid valve duty ratio CPC Duty % 0 — 3%
Generator duty ALT duty % 0%
Fuel pump duty Fuel pump duty % 33%
Va r i a b l e va l v e t i m i n g a d v a n c e a n g l e a m o u n t R V V T a d va n c e a n g l e a m o u n t R d e g 0 d e g
Va r i a b l e va l v e t i m i n g a d v a n c e a n g l e a m o u n t L V V T a d va n c e a n g l e a m o u n t L d e g 0 d e g
Oil flow control solenoid valve duty R OCV duty R % 9.4%
Oil flow control solenoid valve duty L OCV duty L % 9.4%
Oil flow control solenoid valve current R OCV current R mA 64 mA
Oil flow control solenoid valve current L OCV current L mA 64 mA
Fr o nt ox yg e n ( A / F) s en so r cu r r en t va l ue 1 A / F s en s or cu r r e nt va l ue 1 mA 0 . 0 m A
Fr o nt ox yg e n ( A / F) s en so r cu r r en t va l ue 2 A / F s en s or cu r r e nt va l ue 2 mA 0 . 0 m A
Fr o nt ox yg e n ( A / F) s en so r r es is t an ce val ue 1 A / F s en s or r e si st a nc e val u e 1Ω31 Ω