Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 545

VDC(diag)-79

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AG:DTC C0054 BLS ON MALFUNCTION

DTC DETECTING CONDITION:

Defective stop light switch

TROUBLE SYMPTOM:

• ABS does not operate.

• VDC does not operate.

WIRING DIAGRAM:

Vehicle Dynamics Control System <Ref. to WI-67, Vehicle Dynamics Control System.>

B225

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23 24

1 2
3 4

B225

5Dr

4Dr

1
5

3
8

B65

1 2
3 4

1 2 3 4 5

B65

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

1 2

3 4 5

6 7 8 9 10 11 12

13
14

15 16

25
26

21
22

29
30

32 35

33
34

37
38

11 12

B310

B65

B434

B159

R168

B99

B435

5Dr

B159

R168

B99

B434

B435

5Dr

4Dr

VDC00819

VDCCM & H/U

SBF-2

: 4 DOOR MODEL : 4

5 DOOR MODEL : 2

: 4 DOOR MODEL : 3

5 DOOR MODEL : 1

BATTERY

No. 8

MAIN SBF

STOP LIGHT &

BRAKE SWITCH

: 4 DOOR MODEL

: 5 DOOR MODEL

FUSE & RELAY BOX

(F/B)

FUSE

(RELA

Y BLOCK)

7.5A

VDC(diag)-80

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the stop light switch connector.
3) Measure the resistance of stop light switch
terminals.

Connector & terminal

4 door model

(B65) No. 3 — No. 4:

5 door model

(B65) No. 1 — No. 2:

Is the resistance 1 MΩ or more
when switch is OFF (when
pedal is not depressed)?

Go to step

Replace the stop
light switch. <Ref.
to BR-49, Stop
Light Switch.>

INTERVIEW CUSTOMERS.
Make sure that the operation was performed in
which accelerator pedal and brake pedal were
depressed simultaneously (with depressing
brake pedal with left foot).

Were the acceleration pedal
and brake pedal depressed
simultaneously?

System is normal.
(DTC may be
recorded while
brake is applied
during driving.)

Go to step

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

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)-81

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AH:DTC C0054 BLS OFF MALFUNCTION

DTC DETECTING CONDITION:

Defective stop light switch

TROUBLE SYMPTOM:

• ABS does not operate.

• VDC does not operate.

WIRING DIAGRAM:

Vehicle dynamics control system <Ref. to WI-67, Vehicle Dynamics Control System.>

B225

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23 24

1 2
3 4

B225

5Dr

4Dr

1
5

3
8

B65

1 2
3 4

1 2 3 4 5

B65

1 2 3 4

5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20

1 2

3 4 5

6 7 8 9 10 11 12

13
14

15 16

25
26

21
22

29
30

32 35

33
34

37
38

11 12

B310

B65

B434

B159

R168

B99

B435

5Dr

B159

R168

B99

B434

B435

5Dr

4Dr

VDC00819

VDCCM & H/U

SBF-2

: 4 DOOR MODEL : 4

5 DOOR MODEL : 2

: 4 DOOR MODEL : 3

5 DOOR MODEL : 1

BATTERY

No. 8

MAIN SBF

STOP LIGHT &

BRAKE SWITCH

: 4 DOOR MODEL

: 5 DOOR MODEL

FUSE & RELAY BOX

(F/B)

FUSE

(RELA

Y BLOCK)

7.5A

VDC(diag)-82

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

CHECK STOP LIGHT SWITCH.
Check the stop light switch. <Ref. to BR-49,
INSTALLATION, Stop Light Switch.>

Is the installation position of the
stop light switch correct?

Go to step

Adjust the installa-
tion position of the
stop light switch.
<Ref. to BR-49,
INSTALLATION,
Stop Light
Switch.>

CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the stop light switch connector.
3) Measure the resistance of stop light switch
terminals.

Connector & terminal

4 door model

(B65) No. 3 — No. 4:

5 door model

(B65) No. 1 — No. 2:

Is the resistance 1 Ω or less
when the switch is ON (when
pedal is depressed)?

Go to step

Replace the stop
light switch. <Ref.
to BR-49, Stop
Light Switch.>

CHECK STOP LIGHT POWER SUPPLY.
Measure the voltage between stop light switch
terminal and chassis ground.

Connector & terminal

4 door model

(B65) No. 3 (+) — Chassis ground (–):

5 door model

(B65) No. 1 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step

Repair the stop
light power supply
circuit.

CHECK STOP LIGHT SWITCH HARNESS.
1) Disconnect the connector from the
VDCCM&H/U.
2) Measure the resistance between
VDCCM&H/U and stop light switch.

Connector & terminal

4 door model

(B65) No. 4 — (B310) No. 30:

5 door model

(B65) No. 2 — (B310) No. 30:

Is the resistance less than 1 Ω? Go to step

Repair the stop
light switch circuit.

CHECK POOR CONTACT OF CONNEC-
TORS.

Is there poor contact of connec-
tor between stop light switch
and VDCCM&H/U?

Repair the connec-
tor.

Go to step

Is the same DTC displayed?