Subaru Legacy IV (2008 year). Manual - part 935

VDC(diag)-55

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Y: DTC C0042 POWER SUPPLY VOLTAGE FAILURE

DTC DETECTING CONDITION:
Improper VDCCM&H/U power supply voltage
TROUBLE SYMPTOM:
• ABS does not operate.
• EBD may not operate.
• VDC does not operate.

NOTE:
Warning lights go off if voltage returns.
WIRING DIAGRAM:

MAIN SBF

SBF-6

No.33

B310

VDCCM & H/U

BATTERY

GENERATOR

IGNITION
SWITCH

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

VDC00463

VDC(diag)-56

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

CHECK GENERATOR.
1) Start the engine.
2) Run the engine at idle after warming up.
3) Measure the voltage between generator ter-
minal B and chassis ground.

Terminals

Generator B terminal (+) — Chassis
ground (–):

Is the voltage 10 — 15 V?

Go to step 2.

Repair the genera-
tor.

CHECK BATTERY TERMINAL.
Turn the ignition switch to OFF.

Are the positive and negative
battery terminals clamped
tightly?

Go to step 3.

Tighten the termi-
nal.

CHECK VDCCM&H/U INPUT VOLTAGE.
1) Disconnect the connector from the
VDCCM&H/U.
2) Run the engine at idle.
3) Operate devices such as headlights, air
conditioner, defogger, etc. which produce an
electrical load.
4) Measure the voltage between VDCCM&H/U
connector and chassis ground.

Connector & terminal

(B310) No. 28 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 4.

Repair the power
supply circuit.

CHECK VDCCM&H/U GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between
VDCCM&H/U connector and chassis ground.

Connector & terminal

(B310) No. 25 — Chassis ground:

Is the resistance less than 0.5

:? Go to step 5.

Repair the
VDCCM&H/U
ground harness.

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in connec-

tor between generator, battery
and VDCCM&H/U?

Repair the connec-
tor.

Go to step 6.

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-23,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
VDC(diag)-22, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM only.
<Ref. to VDC-10,
REPLACEMENT,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step 7.

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-34, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

VDC(diag)-57

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Z: DTC C0044 TCM COMMUNICATION CIRCUIT

DTC DETECTING CONDITION:
No CAN signal from TCM.
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

Step

Check

Yes

CHECK LAN SYSTEM.
Perform the diagnosis for LAN system. <Ref. to
LAN(diag)-27, OPERATION, Read Diagnostic
Trouble Code (DTC).>

Is there any fault in LAN sys-
tem?

Perform the diag-
nosis according to
DTC for LAN sys-
tem.

Go to step 2.

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in TCM

connector?

Repair the connec-
tor.

Go to step 3.

CHECK TCM.

Is the TCM normal?

Go to step 4.

Replace the TCM.
<Ref. to 4AT-61,
Transmission Con-
trol Module
(TCM).> <Ref. to
5AT-60, Transmis-
sion Control Mod-
ule (TCM).>

Is the same DTC displayed?

Replace the
VDCCM only.

Go to step 5.

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-34, List
of Diagnostic Trou-
ble Code (DTC).>

It results from a
temporary noise
interference.

VDC(diag)-58

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AA:DTC C0045 INCORRECT VDC CONTROL MODULE SPECIFICATIONS

DTC DETECTING CONDITION:
Different control module specification
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

NOTE:
When parameter selection for VDCCM is improper, this DTC may be memorized.

Step

Check

Yes

CHECK VDCCM REPLACEMENT HISTORY. Is there replacement history of

VDCCM alone?

Go to step 2.

Go to step 3.

CHECK VDCCM IDENTIFICATION NUMBER.
Check the identification number on the sticker
attached on the VDCCM side.
AT:

T3 (2.5 L turbo models and OUTBACK 3.0 L
models)
T7 (Sedan 3.0L with 18 inch tire model)
TA (2.5L non-turbo model and sedan 3.0L
with 17 inch tire model)

MT:

T4 (2.5L turbo model)
TB (2.5L non-turbo model)

Is the identification number cor-
rect?

Go to step 4.

Replace the
VDCCM only.

CHECK VDCCM&H/U IDENTIFICATION
NUMBER.
Check the identification number stamped on the
upper side of the H/U.
AT:

T3 (2.5 L turbo models and OUTBACK 3.0 L
models)
T7 (Sedan 3.0L with 18 inch tire model)
TA (2.5L non-turbo model and sedan 3.0L
with 17 inch tire model)

MT:

T4 (2.5L turbo model)
TB (2.5L non-turbo model)

Is the identification number cor-
rect?

Go to step 4.

Replace the
VDCCM&H/U.

CHECK PARAMETER SELECTED FOR VDC-
CM.
<Ref. to VDC(diag)-17, PARAMETER CHECK,
OPERATION, Subaru Select Monitor.>

Does the parameter registered
to the VDCCM match with the
target vehicle?

Go to step 5.

Select and register
the correct param-
eter. <Ref. to
VDC(diag)-16,
PARAMETER
SELECTION,
OPERATION, Sub-
aru Select Moni-
tor.>

CHECK TCM SPECIFICATION.
Check the TCM specification.

Is the specification of TCM
same as vehicle specification?

Go to step 6.

Replace the TCM.
<Ref. to 4AT-61,
Transmission Con-
trol Module
(TCM).> <Ref. to
5AT-60, Transmis-
sion Control Mod-
ule (TCM).>

CHECK AT SYSTEM.
1) Start the engine.
2) Check the DTC in AT system.

Is DTC of AT system displayed? Repair the AT sys-

tem.

Go to step 7.

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