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(diag)-8
Check List for Interview
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Condition a) Brakes Deceleration: G
continuous / intermittent
b) Accelerator Acceleration: G
continuous / intermittent
c) Vehicle speed km/h MPH
Advancing
Accelerating
Reducing speed
Low speed
Turning
Others:
d) Tire inflation pressure Front RH tire: kPa
Fr o n t L H t ir e : kPa
Rear RH tire: kPa
Rear LH tire: kPa
e) Degree of wear Front RH tire:
Fr o n t L H t ir e :
Rear RH tire:
Rear LH tire:
f) Steering wheel Sharp turning
Gentle turning
Straight forward motion
Gentle return
Sharp return
g) Tire/Wheel size Specified size
Except specification ( )
h) Tire variation Summer tire
Studless tire (Brand: )
i) Tire chains are fitted: Yes / No
j) T-type tire is used: Yes / No
k) Condition of suspension alignment:
l) Loading state:
m) Repair parts are used: Yes / No
• Contents:
n) Others:
VDC(diag)-11
Electrical Component Location
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
4. Electrical Component Location
A: LOCATION
(1) VDC control module & hydraulic
control unit (VDCCM&H/U)
(6) VDC indicator light (11) ABS wheel speed sensor
(7) VDC warning light and TCS OFF
indicator light
(12) Yaw rate & lateral G sensor
(2) Relay box (13) Data link connector
(3) Engine control module (ECM) (8) Steering angle sensor (14) Transmission control module
(TCM)(4) Brake warning light (EBD warning
light)
(9) TCS OFF switch
(10) Magnetic encoder (15) Stop light switch
(5) ABS warning light
(4)(5)(6)(7)
(8)
(1)
(2)
(3)
(15)
(14)
(12)
(13)
(11)(10)
(11)(10)
(9)
VDC00359
VDC(diag)-14
Control Module I/O Signal
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Description
Te r m i n a l
No.
(+) — (–)
Input/Output signal
Measured value and measuring conditions
Pow er s up p ly 1 — 43 10 — 15 V w h e n t h e i gn i t io n sw it ch i s ON .
ABS wheel speed
sensor
Front LH wheelPowe r s u pp ly 27 — 4 3 8 . 5 — 1 3. 5 V
Signal 41 5 — 17 mA: Rectangle waveform
Front RH wheelPower supply 42 — 43 8.5 — 13.5 V
Signal 28 5 — 17 mA: Rectangle waveform
Rear LH wheelPower supply 25 — 43 8.5 — 13.5 V
Signal 39 5 — 17 mA: Rectangle waveform
Rear RH wheelPower supply 26 — 43 8.5 — 13.5 V
Signal 40 5 — 17 mA: Rectangle waveform
Ya w r a t e & l a t e r a l G s e n s o r34 — 20 Serial communicationSteering angle sensor
CAN communication line (+) 34 Serial communication
CAN communication line (–) 20 Serial communication
Valve relay power supply 44 — 43 10 — 15 V when the ignition switch is ON.
Motor power supply 45 — 46 10 — 15 V when the ignition switch is ON.
ABS warning light 16 — 43After turning the ignition switch to ON, 10 — 15 V during 1.5
seconds and less than 1.5 V after 1.5 seconds passed.
Brake warning light (EBD warning light) 3 — 43After turning the ignition switch to ON, 10 — 15 V during 1.5
seconds and less than 1.5 V after 1.5 seconds passed.
Stop light switch 18 — 43Less than 1.5 V when the stop light is OFF; otherwise, 10 —
15 V when the stop light is ON.
Subaru Select Monitor 32 — 43 0 ←→ 12 V pulse (in communication)
Ve h i c l e s p e e d o u t p u t s i g n a l 3 3 0 ←→ 5 V pulse
Ground 43 —
Relay box
Relay power supply 2 — 43 10 — 15 V when the ignition switch is ON.
Motor relay drive 30 — 43After turning the ignition switch to ON, 1.5 V after 10 — 15,
motor startup.
Fa i l s afe r e lay d r ive 31 — 4 3 W he n t h e i g ni t io n swit c h i s ON, l es s t ha n 1 . 5 V.
VDC(diag)-15
Control Module I/O Signal
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
B: WIRING DIAGRAM
(1) Battery (16) Rear inlet solenoid valve RH (30) Data link connector
(2) Ignition switch (17) Rear outlet solenoid valve RH (31) TCS OFF switch
(3) VDC control module & hydraulic
control unit (VDCCM&H/U)
(18) Linear valve 1 (32) Steering angle sensor
(19) Linear valve 2 (33) Yaw rate & lateral G sensor
(4) VDC control module (20) Pressure sensor (34)
Tr a n s m i s s i o n c o n t r o l m o d u l e
(TCM)(5) Relay box (21) Stop light switch
(6) Motor relay (22) Stop light (35) Engine control module (ECM)
(7) Fail safe relay (23) VDC indicator light (36) Body integrated unit
(8) Motor (24) VDC warning light and TCS OFF
indicator light
(37)
Fr o nt A B S w he e l sp ee d se n so r L H
(9) Valve relay
(10) Front inlet solenoid valve LH (25) ABS warning light (38)
Fr o nt A B S w he e l sp e ed se n so r
RH(11) Front outlet solenoid valve LH (26) Brake warning light
(12) Front inlet solenoid valve RH (27) Parking brake switch (39) Rear ABS wheel speed sensor LH
(13) Front outlet solenoid valve RH (28) Brake fluid level switch (40) Rear ABS wheel speed sensor
RH(14) Rear inlet solenoid valve LH (29) Combination meter
(15) Rear outlet solenoid valve LH
VDC00366
M
(17)(4)(16)
(19)
(20)
(18)
(38)
(37)
(32)
(33)
(36)
(34)
(35)
(40)
(39)
(15)
(14)
(13)
(12)
(7)
(22)(21)
(31)
(23)(29)
(24)
(25)
(26)
(27) (28)(30)
(1)
(2)
(6)
(11)
(10)
(9)
(8)
(3)
(5)
VDC(diag)-17
Subaru Select Monitor
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
2. READ CURRENT DATA
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 {Brake Control} and press the [YES] key.
3) Press the [YES] key after {VDC AWD AT} is displayed.
4) On the «Brake Control Diagnosis» display screen, select the {Current Data Display/Save}, and then press
the [YES] key.
5) On the «Display Menu» screen, select the data display method and press the [YES] key.
6) Using a scroll key, scroll the display screen up or down until necessary data is shown.
•A list of the support data is shown in the following table.
NOTE:
For details concerning operation procedure, refer to the “SUBARU SELECT MONITOR OPERATION MAN-
UAL”.
Display Contents to be monitored Unit of measure
FR Wheel SpeedWheel speed detected by front ABS wheel speed sensor RH is dis-
played.km/h or MPH
FL Wheel SpeedWheel speed detected by front ABS wheel speed sensor LH is dis-
played.km/h or MPH
RR Wheel SpeedWheel speed detected by rear ABS wheel speed sensor RH is dis-
played.km/h or MPH
RL Wheel SpeedWheel speed detected by rear ABS wheel speed sensor LH is dis-
played.km/h or MPH
Fr o nt / Re ar G S e ns o r Ve h ic le f r on t / re a r ac ce le ra t io n d e te c te d by G se n so r is d i sp layed .m/s2
Lateral G Sensor Vehicle lateral acceleration detected by G sensor is displayed.m/s2
IG power supply voltage Voltage supplied to VDCCM&H/U is displayed. V
Steering Angle Sensor Steering angle detected by steering angle sensor is displayed. deg
Ya w R a t e S e n s o r V e h i c l e a n g u l a r s p e e d d e t e c t e d b y y a w r a t e s e n s o r i s d i s p l a y e d . d e g / s
Pressure Sensor Brake fluid pressure detected by pressure sensor is displayed. bar
ABS Control Flag ABS control condition is displayed. ON or OFF
EBD Control Flag EBD control condition is displayed. ON or OFF
Brake Switch Brake ON/OFF is displayed. ON or OFF
ABS Warning Light ON operation of the ABS warning light is displayed. ON or OFF
EBD Warning Light ON operation of the EBD warning light is displayed. ON or OFF
Motor Relay Signal Motor relay operation signal is displayed. ON or OFF
Motor Relay Monitor Motor relay monitor signal is displayed. ON or OFF
TCS Control Flag TCS control condition is displayed. ON or OFF
Va l ve R e l ay S i g n a l Va l v e r e l ay o p e r a t i o n s i g n a l i s d i s p l ay e d . O N o r O F F
VDC Control Flag VDC control condition is displayed. ON or OFF
VDC Warning Light ON operation of the VDC warning light is displayed. ON or OFF
OFF Light ON/OFF condition of TCS OFF indicator light is displayed. ON or OFF
E/G Control Prohibited Flag Engine control command signal is displayed. 1 or 0
OFF Switch Signal Operation condition of TCS OFF switch is displayed. ON or OFF
Motor Fail Safe Relay Drive
SignalMotor fail safe relay drive signal is displayed. ON or OFF
VDC(diag)-18
Subaru Select Monitor
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
3. CLEAR MEMORY MODE
1) On the «Main Menu», select the {2. Each Sys-
tem Check} and press the [YES] key.
2) On the «System Selection Menu» display
screen, select the {Brake Control} and press the
[YES] key.
3) Press the [YES] key after {VDC AWD AT} is dis-
played.
4) On the «Brake Control Diagnosis» display
screen, select the {Memory Clear} and press the
[YES] key.
5) When “Done” and “Turn ignition switch OFF” are
shown on the display screen, turn the Subaru Se-
lect Monitor and ignition switch to OFF.
NOTE:
For details concerning operation procedure, refer
to the “SUBARU SELECT MONITOR OPERATION
MANUAL”.
4. SEQUENCE CONTROL
5. FREEZE FRAME DATA
NOTE:
•Data stored at the time of trouble occurrence is
shown on display.
•Each time trouble occurs, the latest information
is stored in the freeze frame data in memory.
Display Contents to be monitored
Clear memory? DTC deleting function
Display Contents to be monitoredReference tar-
get
ABS
sequence
control
Operate the valve and
pump motor continuously
to perform the ABS
sequence control.
Sequence Con-
trol.>
VDC
sequence
control
Operate the valve and
pump motor continuously
to perform the VDC
sequence control.
Sequence Con-
trol.>
Display Contents to be monitored
IG CounterNumber of times ignition switch turned to
ON is displayed.
DTC The recorded failure code is displayed.
FR Wheel
Speed
Wheel speed detected by front ABS
wheel speed sensor RH is displayed in
km/h or MPH.
FL Wheel Speed
Wheel speed detected by front ABS
wheel speed sensor LH is displayed in
km/h or MPH.
RR Wheel
Speed
Wheel speed detected by rear ABS
wheel speed sensor RH is displayed in
km/h or MPH.
RL Wheel
Speed
Wheel speed detected by rear ABS
wheel speed sensor LH is displayed in
km/h or MPH.
Ve h i c l e S p e e dVe h i c l e s p e e d c a l c u l a t e d b y V D C c o n t r o l
module is displayed.
G Sensor First
ShaftThe sensor value for a 45° angle crossed
2 axis G sensor is displayed.G Sensor Sec-
ond Shaft
Ya w R a t e S e n -
sor
Ve h i c l e a n g u l a r s p e e d d e t e c t e d b y y a w
rate sensor is displayed.
IG power supply
voltage
Vo l t a g e s u p p l i e d t o V D C c o n t r o l m o d u l e
is displayed.
Steering Angle
Sensor
Steering angle detected by steering
angle sensor is displayed.
Pressure sen-
sor output
Brake fluid pressure detected by pres-
sure sensor is displayed.
Engine SpeedEngine speed on malfunction occur-
rence is displayed.
Acceleration
Opening AngleAcceleration opening is displayed.
Gear positionGear position on malfunction occurrence
is displayed.
Steering Angle
Sensor Malfunc-
tion Code
The recorded steering angle sensor fail-
ure code is displayed?
ABS Control
FlagABS control condition is displayed.
EBD Control
FlagEBD control condition is displayed.
Brake Switch Brake ON/OFF is displayed.
TCS Control
FlagTCS control condition is displayed.
VDC Control
FlagVDC control condition is displayed.
E/G Control Flag
Absolute angle
recognition flag
Whether the absolute angle was deter-
mined is displayed.
OFF Switch Sig-
nal
Operation condition of TCS OFF switch
is displayed.
VDC(diag)-44
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)
Step Check Yes No
1CHECK THE VDCCM&H/U POWER SUPPLY
CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the VDCCM&H/U connector.
3) Turn the ignition switch to ON.
4) Measure the voltage between VDCCM&H/
U connector terminals.
Connector & terminal
(B310) No. 1 (+) — (B310) No. 43 (–):
Is the voltage 10 — 15 V? Go to step 2.Check the genera-
tor, batter y and
VDCCM&H/U
power supply cir-
cuit.
2CHECK OUTPUT OF ABS WHEEL SPEED
SENSOR USING SUBARU SELECT MONI-
TOR.
1) Select {Current Data Display & Save} in
Subaru Select Monitor.
2) Read the ABS wheel speed sensor output
corresponding to the faulty wheel in Subaru
Select Monitor data display mode.
Does the speed indicated on
the display change in response
to the speedometer reading
during acceleration/decelera-
tion when the steering wheel is
in the straight-ahead position?
Go to step 3.Go to step 8.
3CHECK POOR CONTACT IN CONNECTOR.
Tu r n t h e i g n i t i o n s w i t c h t o O F F.
Is there poor contact in con-
nectors between VDCCM&H/U
and ABS wheel speed sensor?
Repair the con-
nector.
Go to step 4.
4CHECK CAUSE OF SIGNAL NOISE.
Make sure the radio wave devices and electric
components are installed correctly.
Are the radio wave devices and
electric components installed
correctly?
Go to step 5.Install the radio
wave devices and
electric compo-
nents properly.
5CHECK CAUSE OF SIGNAL NOISE.
Check if the noise sources (such as an
antenna) are installed near the sensor har-
ness.
Are noise sources installed? Install the noise
sources apart from
sensor harness.
Go to step 6.
6CHECK THE VDCCM&H/U.
1) Connect all the connectors.
2) Erase the memory.
3) Perform the inspection mode.
Mode.>
4) Read the DTC.
Is the same DTC displayed? Replace the
VDCCM&H/U.
ule & Hydraulic
Control Unit
(VDCCM&H/U).>
Go to step 7.
7CHECK OTHER DTC DETECTION.Is any other DTC displayed? Perform the diag-
nosis according to
DTC.
It results from a
temporary noise
interference.
8CHECK INSTALLATION OF ABS WHEEL
SPEED SENSOR.
Is the ABS wheel speed sen-
sor installation bolt tightened
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)?
Go to step 9.Tighten the ABS
wheel speed sen-
sor installation
bolts.
9CHECK ABS WHEEL SPEED SENSOR SIG-
NAL.
1) Install the ABS wheel speed sensor.
2) Prepare an oscilloscope.
3) Check the ABS wheel speed sensor.
INSPECTION, Front ABS Wheel Speed Sen-
sor.>
Does the oscilloscope indicate
the waveform pattern like
shown in the figure when the
tire is slowly turned? Does the
oscilloscope indication repeat
the waveform pattern like
shown in the figure when the
tire is slowly turned in equal
speed for more one rotation?
Go to step 11.Go to step 10.