I have no wheel drive on slippery roads. it says enabled

Check to make sure all of your drive shaft U joints are in good condition. Unless you have a full time 4 wheel drive you shouldn't run on dry pavement in 4 wheel drive for very long as stress builds up in the drive system. 4 wheel drive is best for slippery roads/mud/ dirt conditions.

suggest "n" may be the answer as the lever connects to the transfer case .H is for all wheel drive on slippery roads and 4L is for towing heavy loads when extra torque is required in all wheel drive

Anti-Lock Braking System (ABS)
Purpose Anti-lock brake systems (ABS) - generally also referred to as anti-lock
systems (ALS) - are designed to prevent the vehicle wheels from locking
as a result of the service brake being applied with too much force, especially
on slippery road surfaces.
The idea is to maintain cornering forces on braked wheels to ensure that
the vehicle or vehicle combination retains its driving stability and manoeuvrability
as far as physically possible. The available power transmission
or grip between tyres and carriageway should also be utilised as
far as possible to minimise the braking distance and maximise vehicle
deceleration.
Why ABS? Although today commercial vehicle brakes are designed to a very high
technical standard, braking on slippery roads often results in potentially
dangerous situations. During full or even partial braking on a slippery
road it may no longer be possible to fully transfer the braking force onto
the road due to the low coefficient of friction (friction coefficient (k)) between
the tyres and the carriageway. The braking force is excessive and
the wheels lock up. Locked wheels no longer provide any grip on the
road and are almost incapable of transferring any cornering forces
(steering and tracking forces). This often has dangerous consequences:
- The vehicle becomes unsteerable
- The vehicle breaks away in spite of countersteering, and starts to
swerve.
- The braking distance is significantly increased
- Tractor-trailer combinations or semitrailer trains may break away or
jackknife.
Load sensing valve influence On dry roads today's load sensing valves (ALB) alone are often capable
of preventing the wheels from locking if the vehicle is unladen; they also
help the driver to effectively grade the braking process on wet road surfaces,
but they are unable to prevent locking as such (no slip monitoring).
In addition, they are unable to counteract any overreactions on the
part of the driver, or any variances in frictional or adhesion coefficients
which may apply to different sides of the vehicle, or indeed to its different
axles (?-split road surfaces).
Benefits of ABS: Only the Anti-Lock Brake System (ABS)
- guarantees stable braking characteristics on all road surfaces.
- maintains steerability and generally reduces the braking distance
- prevents vehicle combinations from jackknifing
- reduces tyre wear.
Limits of ABS Although ABS is an effective safety device, it can not suspend the limits
defined by driving physics. Even a vehicle fitted with ABS will become
uncontrollable if driven too fast around a corner.
So ABS is not a licence for a maladjusted style of driving or failure to observe
the correct safety distance.
4
ABS Training Anti-Slip Regulation (ASR)
Anti-Slip Regulation (ASR)
Why ASR? Increasing the engine output (accelerating) on a slippery road surface
can easily lead to the maximum adhesion on one or all powered wheels
being exceeded causing them to spin, especially if the vehicle is unladen
or partially laden.
Spinning wheels when driving off or accelerating represent a safety risk
just like locked wheel do when braking.
Reasons - Wheels that spin transfer just as little cornering force as locked
wheels.
- They also no longer transfer any tractive power onto the road.
Consequences - Vehicles that do not move or get stuck.
- Vehicles that can no longer be steered, jackknife on uphill uphill
gradients, or swerve in corners.
Benefits of ASR ASR prevents the powered wheel from spinning and provides the following
benefits:
- Tractive power and cornering forces are maintained.
- Stable driving behaviour is ensured when moving off, accelerating
and negotiating corners on slippery roads.
- The indicator lamp (if installed) is used to warn the driver of slippery
road conditions.
- Tyre wear is reduced to a minimum, and the motor vehicle's drive
train protected
- The risk of accidents is further reduced.
ASR and ABS: ASR represents a worthwhile addition to an ABS-controlled braking system.
All that is required to turn ABS control into full ABS/ASR control is
an ECU with the additional ASR function and a few additional components
for controlling the differential brake and the engine. This why ASR
is only available in combination with ABS.
Even a differential lock for off-road use and ASR do not exclude but complement
each other.
Limits of ASR The traction capacity of an all-wheel driven commercial vehicle can not
be achieved by a motor vehicle with only one driving axle - not even with
optimal ASR.

Hello, lets test that BMW M5 ABS braking system, OK. First, drive down a street with no traffic. Speed up to 30 to 40 MPH. Then slam on your brakes hard, if the brake petal is pulsating and there a noise like clunk,clunk,clunk,clunk noise. Your BMW ABS is working. If not, then the BMW ABS isn't working.


ABS system and what it does to your BMW. All it amount to is it doesn't lock up the braking system. It just applied the brake and release in micro seconds. This keep the vehicle from sliding side ways on wet roads, snowy roads, icy roads or even on dry roads. In other words, it keeps the front of the BMW in a straight line.



If your BMW ABS isn't do this, you'll need to have the ABS braking system serviced. GB...stewbison

The AWD means All Wheel Drive. Sort of the same as a 4 wheel drive. All the wheels have power at the same time. In a slippery road condition, all tires/wheels can loose traction at the same time causing loose of control - which would be normal. AWD does not mean traction all the time in snow and ice. It still has to be driven with caution and respect to road conditions. Hope this helps.

If you engage the 4x4 on dry non slippery roads, It will pop and snap. Four wheel drive should only be engaged on slippery or off road conditions.

Anti-Lock Braking System (ABS)
Purpose Anti-lock brake systems (ABS) - generally also referred to as anti-lock
systems (ALS) - are designed to prevent the vehicle wheels from locking
as a result of the service brake being applied with too much force, especially
on slippery road surfaces.
The idea is to maintain cornering forces on braked wheels to ensure that
the vehicle or vehicle combination retains its driving stability and manoeuvrability
as far as physically possible. The available power transmission
or grip between tyres and carriageway should also be utilised as
far as possible to minimise the braking distance and maximise vehicle
deceleration.
Why ABS? Although today commercial vehicle brakes are designed to a very high
technical standard, braking on slippery roads often results in potentially
dangerous situations. During full or even partial braking on a slippery
road it may no longer be possible to fully transfer the braking force onto
the road due to the low coefficient of friction (friction coefficient (k)) between
the tyres and the carriageway. The braking force is excessive and
the wheels lock up. Locked wheels no longer provide any grip on the
road and are almost incapable of transferring any cornering forces
(steering and tracking forces). This often has dangerous consequences:
- The vehicle becomes unsteerable
- The vehicle breaks away in spite of countersteering, and starts to
swerve.
- The braking distance is significantly increased
- Tractor-trailer combinations or semitrailer trains may break away or
jackknife.
Load sensing valve influence On dry roads today's load sensing valves (ALB) alone are often capable
of preventing the wheels from locking if the vehicle is unladen; they also
help the driver to effectively grade the braking process on wet road surfaces,
but they are unable to prevent locking as such (no slip monitoring).
In addition, they are unable to counteract any overreactions on the
part of the driver, or any variances in frictional or adhesion coefficients
which may apply to different sides of the vehicle, or indeed to its different
axles (?-split road surfaces).
Benefits of ABS: Only the Anti-Lock Brake System (ABS)
- guarantees stable braking characteristics on all road surfaces.
- maintains steerability and generally reduces the braking distance
- prevents vehicle combinations from jackknifing
- reduces tyre wear.
Limits of ABS Although ABS is an effective safety device, it can not suspend the limits
defined by driving physics. Even a vehicle fitted with ABS will become
uncontrollable if driven too fast around a corner.
So ABS is not a licence for a maladjusted style of driving or failure to observe
the correct safety distance.
4
ABS Training Anti-Slip Regulation (ASR)
Anti-Slip Regulation (ASR)
Why ASR? Increasing the engine output (accelerating) on a slippery road surface
can easily lead to the maximum adhesion on one or all powered wheels
being exceeded causing them to spin, especially if the vehicle is unladen
or partially laden.
Spinning wheels when driving off or accelerating represent a safety risk
just like locked wheel do when braking.
Reasons - Wheels that spin transfer just as little cornering force as locked
wheels.
- They also no longer transfer any tractive power onto the road.
Consequences - Vehicles that do not move or get stuck.
- Vehicles that can no longer be steered, jackknife on uphill uphill
gradients, or swerve in corners.
Benefits of ASR ASR prevents the powered wheel from spinning and provides the following
benefits:
- Tractive power and cornering forces are maintained.
- Stable driving behaviour is ensured when moving off, accelerating
and negotiating corners on slippery roads.
- The indicator lamp (if installed) is used to warn the driver of slippery
road conditions.
- Tyre wear is reduced to a minimum, and the motor vehicle's drive
train protected
- The risk of accidents is further reduced.
ASR and ABS: ASR represents a worthwhile addition to an ABS-controlled braking system.
All that is required to turn ABS control into full ABS/ASR control is
an ECU with the additional ASR function and a few additional components
for controlling the differential brake and the engine. This why ASR
is only available in combination with ABS.
Even a differential lock for off-road use and ASR do not exclude but complement
each other.
Limits of ASR The traction capacity of an all-wheel driven commercial vehicle can not
be achieved by a motor vehicle with only one driving axle - not even with
optimal ASR.

You can change on the run but as a general rule stop to change to 4wd.except 2wd to 4wd high.Just slow down to about 15mph and back off the gas.
2wd high is normal running
4wd high(is full time 4wd)this is slippery roads or muddy roads.
4wd high lock For bad and slower slippery and rocky roads.
4wd low lock is for extreme 4wd conditions
Don't use the last 2 on the main roads or transfercase will be damaged
Hope this helps

check the U-joints and the front axle joints

i have seen this many times on VW passats which are on the same platform. You may need a new abs control unit. if the abs control unit cannot be scanned by a computer, check all fuses. if abs contol unit is needed, there is aftermarket places that can rebuild them, i recommend factory unit.