2006 SUBARU IMPREZA WRX Owners Manual

7-12 Starting and operating
Turbo models
mph (km/h)
Driving tips
Do not drive with your foot resting on the
clutch pedal and do not use the clutch to
hold your vehicle at a standstill on an up-
grade. Either of those actions may cause clutch damage.
Do not drive with your hand resting on the
shift lever. This may cause wear on the
transmission components.
When it is necessary to reduce vehicle
speed due to slow traffic, turning corners,
or driving up steep hills, downshift to a
lower gear before the engine starts to la-
bor.
On steep downgrades, downshift the
transmission to 4th, 3rd or 2nd gear as
necessary; this helps to maintain a safe
speed and to extend brake pad life.
In this way, the engine provides a braking
effect. Remember, if you
“ride ” (over use)
the brakes while descending a hill, they
may overheat and not work properly.
The engine may, on rare occasions, knock
when the vehicle rapidly accelerates or
rapidly pulls away from a standstill. This
phenomenon is not an indication of a
problem in your vehicle.
Driver ’s Control Center Dif-
ferential (DCCD) (WRX-STI)1st 34 (54)
2nd 59 (95)
3rd 85 (136)
When shifting down a gear, ensure
that the vehicle is not travelling at a
speed exceeding the Maximum Al-
lowable Speed for the gear which is
about to be selected. Failure to ob-
serve this precaution can lead to en-
gine over-revving and this in turn
can result in engine damage.
In addition, sudden application of
engine brakes when the vehicle is
travelling on a slippery surface can
lead to wheel locking; as a conse-
quence, control of the vehicle may
be lost and the risk of an accident in-
creased.
Always use the utmost care when
driving. Being overconfident be-
cause you are driving a vehicle with
a driver ’s control center differential
could easily lead to a serious acci-
dent.
700379

Starting and operating 7-13
– CONTINUED –
The driver’s control center differential al-
lows you to freely change the degree of
limitation of the differential action (limited
slip differential (LSD) torque) of your vehi-
cle ’s center differential.
By using the center differential control di-
al, you can set an initial LSD torque to
match the road surface conditions, driving
conditions and your driving style.
1) LSD torque
2) Traction torque
A) Initial LSD torque (adjustable)
B) Mechanical LSD torque
NOTE
If you rapidly depress and release the
accelerator pedal while driving at low
speed, you may hear a knocking sound
from the vicinity of the center differen-
tial and rear differential. This sound oc-
curs because of the structure of the
center differential. It does not indicate
a problem.
Auto mode
In the auto mode, the system estimates
the driving and road conditions using sig-
nals from the wheel speed sensor, throttle
position sensor, steering angle sensor
and brake switch, etc. According to the re-
sult, it electronically and automatically
controls the degree of limitation of the dif-
ferential action (LSD torque) to optimize
the differential action of the center differ-
ential. When the ignition switch is turned
ON, the “AUTO ” indicator light in the com-
bination meter comes on. The system can
be switched to a manual mode.
Manual mode
In the manual mode, you can use the cen-
ter differential control dial to adjust the ini-
In the event of failure of the driver
’s
control center differential, the “ ”
indicator light will flash. Have the
vehicle inspected by your SUBARU
dealer.
700378
LOCK1
2A
B
700123

7-14 Starting and operating
tial LSD torque as desired. When this
mode is selected, the “AUTO ” indicator
light in the combination meter goes off.
Manual switch
Press the “DCCD-MANU ” switch on the
center console to switch from auto mode
to manual mode. The “AUTO ” indicator
light in the combination meter will go off.
Press the switch again to go back to auto
mode. The “AUTO ” indicator light in the
combination meter will come on.
Center differential control dial and
indicator light
The control dial is located beside the park-
ing-brake lever. By turning the control dial
forward and rearward, it is possible to
change the initial LSD torque.
The center-differential indicator lights in
the combination meter give six levels of in-
dication. The indicator lights and control
dial are linked; when the dial is turned to
change the initial LSD torque, the illumina-
tion position of the indicator lights chang-
es accordingly. Turn the dial forward to increase the initial
LSD torque; when the white line on the
dial reaches the frontmost position, the ini-
tial LSD torque setting is maximum. The
center differential will then be almost com-
pletely locked and the
“LOCK ” indicator
light will come on.
MANU
700356
700125
700357

Starting and operating 7-15
Turn the dial rearward to reduce the initial
LSD torque; when the white line reaches
the rearmost position, the initial LSD
torque will be minimum and the “ ” indi-
cator light will come on. Under this condi-
tion, only the Mechanical LSD torque will
limit the differential action.
NOTE
A higher initial LSD torque setting
gives the vehicle greater traction when
driving straight ahead but makes cor-
nering more difficult. Remember this
when adjusting the initial LSD torque.
In general, higher initial LSD torque
settings assist driving on slippery
roads and lower settings for non-slip-
pery roads. If you become stuck in
snow or mud, turning the center differ-
ential control dial to the frontmost po-
sition will help move the vehicle out.
(The “LOCK ” indicator will come on at
the frontmost position.)
During cornering or when making
turns (especially when getting into the
garage), the rotational difference be-
tween the front and rear wheels may
cause a braking effect accompanied by vibration and noise. This does not indi-
cate a problem. The phenomenon will
disappear when you turn the center dif-
ferential control dial to the rearmost
position (minimum initial LSD torque
position).
Use the center-differential indicator
light only as a rough indication of the
initial LSD torque.
If you operate the center differential
control dial while quickly accelerating
or turning a tight corner, you may feel
slight shocks. This is due to differential
action by the center differential and
does not indicate a problem.
Temporary release
When the driver stops the vehicle and
pulls the parking-brake lever after manual-
ly setting the initial LSD torque, the LSD
torque is temporarily minimized. However
the indicator in the combination meter
continues to show the driver ’s selected ini-
tial LSD torque. When the driver releases
the parking-brake lever, the initial LSD
torque set by the driver is restored.
Do not turn the control dial when
a wheel slippage occurs. Wait un-
til the wheelspin has been
brought under control.
700358
Under any of the following condi-
tions, turn the center differential
control dial to the rearmost posi-
tion to minimize the initial LSD
torque:
When a temporary spare tire is
installed
When your vehicle is towed
When the vehicle is stopped
with the manual mode selected

7-16 Starting and operating
Automatic transmission
The automatic transmission is electroni-
cally controlled with 4-forward speeds and
1-reverse speed.
NOTE
When the engine coolant tempera-
ture is still low, your vehicle ’s automat-
ic transmission will up-shift at higher
engine speeds than when the coolant
temperature is sufficiently high in or-
der to shorten the warm-up time and
improve driveability. The gearshift tim-
ing will automatically shift to the nor-
mal timing after the engine has warmed
up.
Immediately after ATF (automatic
transmission fluid) is replaced, you
may feel that the automatic transmis-
sion operation is somewhat unusual.
This results from invalidation of data
the on-board computer has collected
and stored in memory to allow the
transmission to shift at the most ap-
propriate times for the current condi-
tion of your vehicle. Optimized shifting
will be restored as the vehicle contin-
ues to be driven for a while.
Selector lever for automatic
transmission
Do not shift from the “P ” or “N ” po-
sition into the “D ”, “3 ”, “2 ”, “1 ” or
“ R ” position while depressing the
accelerator pedal. This may cause
the vehicle to jump forward or back-
ward.
Shift into the “P ” or “R ” position
only after the vehicle is complete-
ly stopped. Shifting while the ve-
hicle is moving may cause dam-
age to the transmission.
Do not race the engine for more
than five seconds in any position
except the “N ” or “P ” position
when the brake is set or when
chocks are used in the wheels.
This may cause the automatic
transmission fluid to overheat.
Avoid shifting from one of the for-
ward driving positions into the “ R ” position or vice versa until the
vehicle has completely stopped.
Such shifting may cause damage
to the transmission.
When parking the vehicle, first se-
curely apply the parking brake
and then place the selector lever
in the “P ” position. Avoid parking
for a long time with the selector le-
ver in any other position as doing
so could result in a dead battery.
700034

Starting and operating 7-17
– CONTINUED –
: With the brake pedal depressed,
move the lever along the gate.
: Move the lever along the gate.
The selector lever has seven positions.
P (Park)
This position is for parking the vehicle and
starting the engine.
In this position, the transmission is me-
chanically locked to prevent the vehicle
from rolling freely.
When you park the vehicle, first set the
parking brake fully, then shift into the “P ”
position. Do not hold the vehicle with only
the transmission.
A shift interlock function is employed in
the automatic transmission system to en- sure safe starting of the vehicle.
To shift the selector lever from the
“P ” to
the any other position, you have to de-
press the brake pedal fully when the igni-
tion switch is in the “ON ” position. This
prevents the vehicle from lurching when it
is started.
If the shift lever does not move from the “ P ” position with the brake pedal de-
pressed, refer to the “Shift lock release ”
section in this chapter.
R (Reverse)
This position is for backing the vehicle.
To shift from the “N ” to “R ” position, first
stop the vehicle completely then move the
lever to the “R ” position.
N (Neutral)
This position is for restarting a stalled en-
gine.
In this position the wheels and transmis-
sion are not locked. In this position, the
transmission is neutral; the vehicle will roll
freely, even on the slightest incline unless
the parking brake or foot brake is on.
Avoid coasting with the transmission neu-
tral.
During coasting, there is no engine brak-
ing effect.
NOTE
If you stop the engine with the selector
lever in the “N ” position, move the se-
lector lever to the “P ” position immedi-
ately. Otherwise, you may find that the
selector lever soon cannot be moved
to the “P ” position. If you find that the
selector lever cannot be moved from
the “N ” position to the “P ” position,
turn the ignition switch to the “ON ” po-
sition and try again.
D (Drive)
This position is for normal driving.
The transmission automatically shifts into
a suitable gear from 1st to 4th according to
the vehicle speed and the acceleration
you require.
When more acceleration is required in this
position, press the accelerator pedal fully
to the floor and hold that position. The
transmission will automatically downshift
to 3rd, 2nd or 1st gear. When you release
the pedal, the transmission will return to
700332
Do not drive the vehicle with the se-
lector lever in the “N ” (neutral) posi-
tion. Engine braking has no effect in
this condition and the risk of an ac-
cident is consequently increased.

7-18 Starting and operating
the original gear position.
While climbing a grade
When driving up hill, undesired upshift to
4th gear is prevented from taking place
when the accelerator pedal is released.
This minimizes the chances of subse-
quent downshifting to a lower gear when
accelerating again. This prevents repeat-
ed upshifting and downshifting resulting in
a smoother operation of the vehicle.
NOTE
The transmission may downshift to
2nd or 1st gear, depending on the way
the accelerator pedal is pressed to ac-
celerate the vehicle again.
While going down a hill
When descending a steep hill, depressing
the brake pedal will cause the transmis-
sion to downshift to 3rd gear, thus apply-
ing engine braking. Reacceleration for a
short time will cause the transmission to
upshift normally.
NOTE
In some cases, depressing the brake
pedal on a downhill grade does not re-
sult in an automatic downshift to 3rd
gear. This can happen when the auto-
matic transmission fluid temperature is
very low, for example, during driving shortly after the vehicle has been
parked for an extended period of time.
When the ATF temperature has risen to
a certain level, automatic downshift
normally takes place. In the meantime,
downshift manually for engine braking
as required.
Also, downshifting when braking
downhill will not occur at speeds
above approximately 48 mph (78 km/h).
3 (Third)
This position is for using engine braking
when going down a hill or for climbing a
grade.
The transmission automatically shifts into
a suitable gear from 1st to 3rd according
to the vehicle speed and the acceleration
you require.
When more acceleration is required in this
position, press the accelerator pedal fully
to the floor and hold that position. The
transmission will automatically downshift
to 2nd or 1st gear. When you release the
pedal, the transmission will return to the
original gear position.
2 (Second)
This position is for using engine braking
when going down a hill or for climbing a
steep grade.
In this position, the transmission holds in the 2nd gear.
Use this position when starting off from a
standstill on slippery road surfaces such
as mud or snow. It will ensure greater trac-
tion.
1 (First)
This position is for driving up or down very
steep grades, or driving through mud or
sand, or on slippery surfaces. In this posi-
tion, the transmission holds in the 1st
gear.
Maximum speeds
The following tables show the maximum
speeds that are possible with each differ-
ent gear.
When shifting down a gear, it is important
to confirm that the current vehicle speed is
not in excess of the Maximum Allowable
Speed of the gear which is about to be se-
lected.
mph (km/h)
Non-turbo models Turbo models
1 28 (45) 28 (45)
2 62 (100) 65 (104)
3 97 (156) 104 (167)

Starting and operating 7-19
– CONTINUED –
NOTE
In order to prevent over-revving during
deceleration of the vehicle, the trans-
mission will remain in the current gear
if the speed of the vehicle is in excess
of the Maximum Allowable Speed for
the gear to which the selector lever has
been moved.
Driving tips
Always apply the foot or parking brake
when the vehicle is stopped in the “D ”, “3 ”,
“ 2 ”, “1 ” or “R ” position.
Always set the parking brake when parking your vehicle. Do not hold the vehi-
cle with only the transmission.
Do not keep the vehicle in a stationary
position on an uphill grade by using the “ D ”, “3 ”, “2 ”, or “1 ” position. Use the brake
instead.
The engine may, on rare occasions, knock
when the vehicle rapidly accelerates or
rapidly pulls away from a standstill. This
phenomenon is not an indication of a
problem in your vehicle.
Shift lock release
If the selector lever does not move from
the “P ” position with the brake pedal de-
pressed and the ignition switch in the “ON ”
position, perform the following steps:
To override the shift lock:
1. Set the parking brake and stop the en-
gine.
2. Take out the screwdriver from the tool
bag.
3. Remove the cover by prying on the
edge with the screwdriver.
4. Insert the screwdriver into the hole.
5. Push down on the screwdriver and
move the selector lever from the “P ” to the
“ N ” position.
6. Remove the screwdriver from the hole.
Depress the brake pedal and start the en-
When shifting down a gear, ensure
that the vehicle is not travelling at a
speed exceeding the Maximum Al-
lowable Speed for the gear which is
about to be selected. Failure to ob-
serve this precaution can lead to en-
gine over-revving and this in turn
can result in engine damage.
In addition, sudden application of
engine brakes when the vehicle is
travelling on a slippery surface can
lead to wheel locking; as a conse-
quence, control of the vehicle may
be lost and the risk of an accident in-
creased.
700059
700060