Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 527

VDC(diag)-7

Check List for Interview

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

4. STATE OF VDC OFF INDICATOR LIGHT

NOTE:

This check list for interview is applied to 5MT model.

VDC OFF indicator
light comes on.

Always
Sometimes
Only once
Does not illuminate

• When/How long does it illuminate?

Ignition key position

LOCK
ACC
ON (before starting engine)
START
ON (after starting engine, engine is running)
ON (after starting engine, engine is at a standstill)

Timing

Immediately after turning the ignition switch to ON
Immediately after turning the ignition switch to START
While accelerating

—

km/h

—

MPH

While driving at a constant speed

km/h

MPH

While decelerating

—

km/h

—

MPH

When turning to the right

Steering angle:

deg

Steering time:

Sec.

When turning to the left

Steering angle:

deg

Steering time:

Sec.

When other electrical parts are operating

• Part name:
• Operating condition:

VDC(diag)-8

Check List for Interview

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

5. CONDITIONS UNDER WHICH TROUBLE OCCURS

Environment

a) Weather

Fine
Cloudy
Rainy
Snowy
Others:

b) Ambient temperature

°C (°F)

c) Road

Inner city
Suburbs
Highway
Local street
Uphill
Downhill
Paved road
Gravel road
Muddy road
Sandy place
Straight road
Sharp curve
Gentle curve
S-curve
Road with a slope on both sides
Others:

d) Road surface

Dry
Wet
Covered with fresh snow
Covered with hardened snow
Frozen slope
Others:

VDC(diag)-9

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
When accelerating
While decelerating
At low speed
When turning
Others:

d) Tire inflation pressure

Front RH tire:

kPa

Front LH tire:

kPa

Rear RH tire:

kPa

Rear LH tire:

kPa

e) Degree of wear

Front RH tire:

mm (in)

Front LH tire:

mm (in)

Rear RH tire:

mm (in)

Rear LH tire:

mm (in)

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 chain is attached:

Yes /

No

j) Using T-type tires:

Yes /

No

k) Condition of suspension alignment:
l) Load condition:
m) Repaired parts are used:

Yes /

No

• Content:
n) Others:

VDC(diag)-10

General Description

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

3. General Description

A: CAUTION

1. SUPPLEMENTAL RESTRAINT SYSTEM

“AIRBAG”

Airbag system wiring harness is routed near the

ABS wheel speed sensor and VDCCM&H/U.
CAUTION:

• Do not use electrical test equipment on wir-

ing harness and connector circuits of the air-

bag system.

• Be careful not to damage the airbag system

wiring harness when servicing the ABS wheel

speed sensor and VDCCM&H/U.

B: INSPECTION

Before performing diagnosis, check the following

items which might affect VDC problems.

1. BATTERY

Measure the battery voltage and check electrolyte.
Standard voltage:

12 V or more

Specific gravity:

1.260 or more

2. GROUND

Check the tightening torque of the ground bolt for

VDC.

3. BRAKE FLUID

1) Check the brake fluid level.

2) Check the brake fluid for leaks.

4. HYDRAULIC UNIT

Check the hydraulic unit.

• When using the brake tester <Ref. to VDC-10,

CHECKING THE HYDRAULIC UNIT ABS OPERA-

TION WITH THE BRAKE TESTER, INSPECTION,

VDC Control Module and Hydraulic Control Unit

(VDCCM&H/U).>

• When not using the brake tester <Ref. to VDC-9,

CHECKING THE HYDRAULIC UNIT ABS OPERA-

TION BY PRESSURE GAUGE, INSPECTION,

VDC Control Module and Hydraulic Control Unit

(VDCCM&H/U).>

5. BRAKE DRAG

Check for brake drag.

6. BRAKE PAD AND ROTOR

Check the brake pad and rotor.

• Front <Ref. to BR-16, INSPECTION, Front Brake

Pad.> <Ref. to BR-17, INSPECTION, Front Disc

Rotor.>

• Rear <Ref. to BR-26, INSPECTION, Rear Brake

Pad.> <Ref. to BR-28, INSPECTION, Rear Disc

Rotor.>

7. TIRES

Check the tire specifications, tire wear and air pres-

sure. <Ref. to WT-2, SPECIFICATION, General

Description.>