Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 552

VDC(diag)-107

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

WIRING DIAGRAM:

Engine electrical system <Ref. to WI-32, Engine Electrical System.>

VDC00891

B136

C:

B135

B:

B9

C17

C2

8

B107

B440

B441

1
2

B310

35

10

B441

B440

1

1

B: B135

29

4

3

1

2

7

6

5

10 11 12 13 14 15

25

24

16

30

9

8

17 18 19

20
28

21 22 23

32

31

26 27

33

34 35

35

27

16

10 11 12 13 14 15

25

24

30

9

8

7

17 18 19 20
28

21 22 23

29

32

31

1

2

3

4

5

6

26

33 34

B136

C:

2

1

B107

25

22

24

23

21

20

46

45

44

43

42

41

13

12

40

39

38

37

19

18

17

16

15

14

11

10

36

35

34

33

32

31

1

3

2

30

29

28

27

26

9

8

7

6

5

4

B310

5

4

3

2

1

ECM

E

SBF-

8

VDCCM & H/U

IG 2 RELAY

CLUTCH SWITCH

BATTERY

No.

4

MAIN SBF

VDC(diag)-108

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK LAN SYSTEM.
Perform the diagnosis for LAN system. <Ref. to
LAN(diag)-2, Basic Diagnostic Procedure.>

Is there any fault in LAN sys-
tem?

Perform the diag-
nosis according to
DTC for LAN sys-
tem. <Ref. to
LAN(diag)-32, List
of Diagnostic Trou-
ble Code (DTC).>

Go to step

2.

2

CHECK CLUTCH SIGNAL USING SUBARU
SELECT MONITOR.
1) Select “Current Data Display & Save” on the
Subaru Select Monitor. <Ref. to VDC(diag)-19,
READ CURRENT DATA, OPERATION, Subaru
Select Monitor.>
2) Read the «Clutch Signal».

Is “OFF” displayed when the
clutch pedal is not depressed,
and is “ON” displayed when
depressed?

Go to step

5.

Go to step

3.

3

CHECK CLUTCH SIGNAL OF ECM USING
SUBARU SELECT MONITOR.
1) Select “Current Data Display & Save” on
Subaru Select Monitor. <Ref. to
EN(H4DOTC)(diag)-41, READ CURRENT
DATA FOR ENGINE (NORMAL MODE),
OPERATION, Subaru Select Monitor.>
2) Read the «Clutch Signal».

Is “OFF” displayed when the
clutch pedal is not depressed,
and is “ON” displayed when
depressed?

Go to step

5.

Go to step

4.

4

CHECK HARNESS BETWEEN ECM AND
CLUTCH SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
clutch switch.
3) Measure the resistance of harness between
ECM and clutch switch connector.

Connector & terminal

(B135) No. 9 — (B107) No. 2:

Is the resistance less than 1 Ω? Repair the power

supply circuit of
clutch switch. Or
replace the clutch
switch. <Ref. to
CL-33, Clutch
Switch.>

Repair the harness
between ECM and
clutch switch con-
nector.

5

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-27,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
VDC(diag)-26, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM only.
<Ref. to VDC-12,
REPLACEMENT,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step

6.

6

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-48, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

VDC(diag)-109

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

BA:DTC C0081 SYSTEM FAILURE

DTC DETECTING CONDITION:

VDC long time sequential control

TROUBLE SYMPTOM:

• ABS does not operate.

• VDC does not operate.

Step

Check

Yes

No

1

CHECK POOR CONTACT OF CONNECTOR. Is there poor contact of the

VDCCM&H/U and yaw rate & G
sensor connector?

Repair the connec-
tor.

Go to step

2.

2

CHECK VDCCM&H/U.
1) Replace the yaw rate & G sensor. <Ref. to
VDC-20, Yaw Rate and G Sensor.>
2) Connect all connectors.
3) Clear the memory. <Ref. to VDC(diag)-27,
Clear Memory Mode.>
4) Perform the Inspection Mode. <Ref. to
VDC(diag)-26, Inspection Mode.>
5) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM&H/U.
<Ref. to VDC-8,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Malfunction is
found in original
yaw rate & G sen-
sor.

VDC(diag)-110

General Diagnostic Table

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

13.General Diagnostic Table

A: INSPECTION

Symptoms

Main probable cause

Other probable cause

Poor brake per-
formance

Long braking/
stopping dis-
tance

• VDCCM&H/U
• Brake pad
• Aeration to brake line
• Tire specifications, tire wear and air
pressures
• Incorrect wiring or piping connections

• Defective ABS wheel speed sensor or sensor
gap
• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & G sensor or improper
installation
• Master cylinder
• Brake caliper
• Disc rotor
• Brake pipe
• Brake booster

Wheel lock

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Incorrect wiring or piping connections

• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & G sensor or improper
installation
• Brake caliper
• Brake pipe

Brake drag

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Master cylinder
• Brake caliper
• Parking brake
• Axle and wheels
• Brake pedal play

• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & G sensor or improper
installation
• Brake pad
• Brake pipe

Long brake
pedal stroke

• Aeration to brake line
• Brake pedal play

• VDCCM&H/U
• Master cylinder
• Brake caliper
• Brake pad
• Brake pipe
• Brake booster

Vehicle vertical
pitching

• VDCCM&H/U
• Road surface (uneven)
• Suspension play or fatigue (reduced
damping)
• Incorrect wiring or piping connections

• Defective ABS wheel speed sensor or sensor
gap
• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & G sensor or improper
installation

Poor brake per-
formance

Unstable or
uneven braking

• VDCCM&H/U
• Defective ABS wheel speed sensor or
sensor gap
• Brake caliper
• Brake pad
• Road surface (uneven)
• Tire specifications, tire wear and air
pressures
• Incorrect wiring or piping connections

• Defective ABS wheel speed sensor or sensor
gap
• Defective steering angle sensor or improper
neutral position
• Defective yaw rate & G sensor or improper
installation
• Master cylinder
• Disc rotor
• Brake pipe
• Axle and wheels
• Road with crowns or banks
• Suspension play or fatigue (reduced damping)