Ford Expedition (2018 year). Manual — part 51

PRINCIPLE OF OPERATION

The traction control system helps avoid
drive wheel spin and loss of traction.

If your vehicle begins to slide, the system
applies the brakes to individual wheels
and, when needed, reduces engine power
at the same time. If the wheels spin when
accelerating on slippery or loose surfaces,
the system reduces engine power in order
to increase traction.

USING TRACTION CONTROL

WARNING

The stability and traction control
light illuminates steadily if the
system detects a failure. Make sure

you did not manually disable the traction
control system using the switch. If the
stability control and traction control light
is still illuminating steadily, have the
system serviced by an authorized dealer
immediately. Operating your vehicle with
traction control disabled could lead to an
increased risk of loss of vehicle control,
vehicle rollover, personal injury and death.

The system automatically turns on each
time you switch the ignition on.

If your vehicle is stuck in mud or snow,
switching traction control off may be
beneficial as this allows the wheels to spin.

Note:

When you switch traction control off,

stability control remains fully active.

Switching the System Off

E166706

The switch for the stability and traction
control system is on the instrument panel.

When you switch the system off, a
message and an illuminated icon appear
on the instrument cluster.

Use the switch again to return the traction
control system to normal operation.

Your vehicle may have MyKey restrictions
regarding this feature. See Principle of
Operation

(page 60).

System Indicator Lights and
Messages

E138639

The stability and traction control
light temporarily illuminates on
engine start-up and flashes:

•

When a driving condition activates
either of the systems.

•

If a problem occurs in either of the
systems.

E130458

The stability and traction control
off light temporarily illuminates
on engine start-up and stays on:

•

When you switch the traction control
system off.

•

When you select an alternative stability
control mode.

PRINCIPLE OF OPERATION

WARNINGS

Vehicle modifications involving
braking system, aftermarket roof
racks, suspension, steering system,

tire construction and wheel and tire size
may change the handling characteristics
of your vehicle and may adversely affect
the performance of the electronic stability
control system. In addition, installing any
stereo loudspeakers may interfere with
and adversely affect the electronic stability
control system. Install any aftermarket
stereo loudspeaker as far as possible from
the front center console, the tunnel, and
the front seats in order to minimize the risk
of interfering with the electronic stability
control sensors. Reducing the
effectiveness of the electronic stability
control system could lead to an increased
risk of loss of vehicle control, vehicle
rollover, personal injury and death.

Remember that even advanced
technology cannot defy the laws of
physics. It’s always possible to lose

control of a vehicle due to inappropriate
driver input for the conditions. Aggressive
driving on any road condition can cause
you to lose control of your vehicle
increasing the risk of personal injury or
property damage. Activation of the
electronic stability control system is an
indication that at least some of the tires
have exceeded their ability to grip the road;
this could reduce the operator’s ability to
control the vehicle potentially resulting in
a loss of vehicle control, vehicle rollover,
personal injury and death. If your electronic
stability control system activates, SLOW
DOWN.

The system automatically turns on each
time you switch the ignition on.

If a fault occurs in either the stability
control or the traction control system, you
may experience the following conditions:

•

The stability and traction control light
illuminates steadily.

•

The stability control and traction
control systems do not enhance your
vehicle's ability to maintain traction of
the wheels.

If a driving condition activates either the
stability control or the traction control
system you may experience the following
conditions:

•

The stability and traction control light
flashes.

•

Your vehicle slows down.

•

Reduced engine power.

•

A vibration in the brake pedal.

•

The brake pedal is stiffer than usual.

•

If the driving condition is severe and
your foot is not on the brake, the brake
pedal may move as the system applies
higher brake force.

The stability control system has several
features built into it to help you maintain
control of your vehicle:

Electronic Stability Control

The system enhances your vehicle’s ability
to prevent skids or lateral slides by
applying brakes to one or more of the
wheels individually and, if necessary,
reducing engine power.

Roll Stability Control

The system enhances your vehicle’s ability
to prevent rollovers by detecting your
vehicle’s roll motion and the rate at which
it changes by applying the brakes to one
or more wheels individually.

Traction Control

The system enhances your vehicle’s ability
to maintain traction of the wheels by
detecting and controlling wheel spin. See
Using Traction Control

(page 207).

E72903

A

A

A

B

B

B

B

Vehicle without stability control
skidding off its intended route.

A

Vehicle with stability control
maintaining control on a slippery
surface.

B

USING STABILITY CONTROL

Stability Control and Traction
Control with Roll Stability
Control™ (RSC™)

The system automatically activates when
you start your engine. You can switch off
the electronic stability control and roll
stability control portions of the system
below 35 mph (56 km/h). When the
transmission is in reverse (R), they are
disabled. You can switch off the traction
control portion of the system
independently. See Using Traction
Control

(page 207).

Stability Control and Traction Control with RSC Features

Traction

control system

Electronic

stability

control

Roll stability

control

Stability

control OFF

light

Button func-

tions

Enabled

Enabled

Enabled

Illuminated
during bulb

check

Default at start-

up

Disabled

1

Enabled

1

Enabled

Illuminated

Button pressed

momentarily

Stability Control and Traction Control with RSC Features

Disabled

4

Disabled

Disabled

Flashes then

illuminated

solid

2

Button pressed

and held for

more than 5

seconds at

vehicle speed

under 35 mph

(56 km/h)

Disabled

1

Enabled

1

Enabled

Illuminated

Vehicle speed

exceeds 35 mph
(56 km/h) after

button is

pressed and

held for more

than 5 seconds

Enabled

Enabled

Enabled

Not illuminated

Button pressed

again after

deactivation

Disabled

4

Disabled

Disabled

Illuminated

Button not

pressed and the

transfer case is

switched to 4X4

Low

3

1

The traction control system may still be enabled but with higher entry thresholds

compared to the full system. The electronic stability control entry thresholds are higher
compared to the full system.

2

When you press and hold the button for more than 5 seconds the indicator lamp blinks

for three seconds.

3

Your vehicle may or may not have this feature available. When you select 4X4 Low the

stability control light illuminates and all stability control with RSC features are disabled.

4

Engine traction control and two-wheel spin brake traction control functions are disabled.

Single wheel spin traction control is always enabled.