Abs system fault

1. I would not be concerned because if there was a failure in the ABS you would definitely get an ABS warning light and the ABS and most likely the stability control/traction control systems (with added warning lights) will all switch off .

2. You can test if the ABS is operational. On a very quiet damp surface, straight, wide road( with NO other cars around), apply your brakes hard from a very low speed - up to 20 mph ONLY driving in a straight line - until the car stops. The front brakes should attempt to lock up under hard braking and if the ABS is operational you will feel it kick in and the brake pedal will pulsate as the ABS constantly allows brake pressure and then releases it to prevent the wheels from locking up on the damp road. If the ABS does not kick in be ready to release the brake pedal quickly to allow the wheels to rotate so you can steer the car safely. Without the ABS the front wheels should begin to lock up on the damp road surface due to the low level of tire grip. ONLY test this at very low speed and ONLY when driving in a straight line on a straight section of wide road with no other vehicles around.

the ABS is anti brake skid which is designed to stop wheel lock up under brakes and allow steering control at all times
it was originally designed for aircraft to stop the under carriage from being ripped from the plane when the wheels (under brakes on landing ) hit a wet patch , snow or ice on the runway
it works by each wheel having a segmented sender that is read by a sensor and this impulse switches on valves in the electric pump in the hydraulic system so that when the wheel stops turning ,brake pressure to that wheel is released momentarily and then reapplied when the wheel turns again
the person using the brake still feels the same brake pressure under the foot and in extreme situations will feel the brake pedal pulsate
Now the ECM continually monitors the ABS system and when fluid sensors, or electronic sensors fall outside set parameters , the ABS light comes on to let you know that there is a problem with the brakes
you should now be having the fault codes read to find the reason for the light and have it repaired as in some systems ,if the repairs are not effected then the vehicle is put into limp mode by the ECM and that reduces the power available and the speed of the vehicle.

The ABS is controlled from the sensors at the wheels . The sensors signal when the wheel stops turning and the ABS releases the brake pressure to that wheel to allow it to turn again while maintain pressure to the other brakes. It has nothing to do with weather conditions or road conditions-- just wheels turning under brakes Under normal driving and brake applications you will not notice ABS operation as it will not be working. You will only notice the ABS assistance when you are under very heavy brakes and the sensation is a pulsing in the brake pedal under your foot. Run the fault code to check for recorded faults in the ABS or have an accredited brake shop specialist check out your concerns

ABS Braking System being activated for some reason

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.

Check & replace if necessary the brake pedal switch placed above pedals on the support.
If the problem still occurs you might access the ABS & ESP ECU (Electronic Control Unit) using diagnostic equipment connected to the data link connector of the car, in order to pull out all DTC (Diagnostic Trouble Codes) memored.
Then you will be able to replace bad piece(s) and fix the problem by erasing all DTC stocked inside ABS ECU & reset it.

The ESP system means the Electronic Stability Program. If the ESP lights on the dashboard permanently the ESP system is faulty. You must access the ESP Electronic Control Unit (ECU) memory for pull out all DTC (Diagnostic Trouble Codes), using diagnostic equipment connected to the data link connector of the car. Then you will be full informed about bad pieces (e.g.: brake pedal switch, front right wheel abs sensor interrupted, ...). After bad pieces replacement you will be able to erase all faults memored by ESP ECU, in other words reset the ESP system and turn off the warning lamp on dashboard.
I'm convinced that your brake pedal switch is faulty because the glow plug warning sign went ON after ESP warning light. Just replace the brake pedal switch, see if rear stop lamps light when press the brake pedal, and test the car on the road.
Good Luck!

The ABS warning light means there is a malfunction in the anti lock system on the brakes. This will not affect the conventional braking system on the car which will continue to operate normally.

The car is safe to drive as long as you recognize that it will now be possible to lock up your wheels under hard braking or when braking in slippery conditions where the tires have poor grip.

The problem with the ABS malfunction is that you no longer have an anti -lock assistance on the brake system so in certain conditions, such as on a wet road, you will be able to lock up the wheels on the car when you brake hard. The anti-lock system identifies and retards lock up (by releasing brake pressure on a wheel or wheels) and allows the wheels to keep turning slowly even when you have full pressure being applied on the brake pedal.

The ABS system relies on sensors and if one or more fails you will get an ABS warning. It could be a faulty or dead sensor but it is impossible to say without testing and inspecting the vehicle.

The ABS has it's own fuse so you can check the fuse box in the car to ensure the fuse has not blown. The fuse location is shown in the car's owner's manual. A blown fuse would trigger a warning.

You should take the car to a competent brake specialist to have it checked and the problem rectified.

It's much safer to have the ABS in operation.

Sounds like your car is reporting a fault with the anti lock braking system. Sometimes this can be caused by a faulty sensor. Whilst the car still has brakes it could be that their anti -lock function is no longer working and this would compromise your brakes at the limit in an accident situation. To test, and in the process perhaps allow the sensor to reset, find a quiet stretch of road free of other road users, especially users behind you. Do an emergency stop from about 40mph by just stamping on the brakes as hard as you can. If the ABS is still working you will feel back through the foot pedal a shuddering sensation. If there is no shuddering and the wheels lock out and car skids to a stop then your abs unit and braking system need a look at. Check your brake fluid level and check your ABS sensors and cables for integrity. If everything looks OK but the fault still remains then take it to the shop for a complete diagnostic study.

yeah you mostlikey have a abs pressure switch problem. which helps in the power assist , and or the seal in the brake booster is going bad

Anti-Lock Control —Vehicles Built After 03/2002 The 3-channel anti-lock brake system consists of the following components:

• front wheel speed sensors
• front wheel speed sensor rings
• hydraulic control unit (HCU)
• Anti-lock brake control module (ECU)
• rear wheel speed sensor
• rear wheel speed sensor rings
• yellow anti-lock brake warning indicator

The 4-channel anti-lock brake system with traction control and stability assist system consists of the following components:

• active brake booster with integral solenoid
• brake booster release switch
• front wheel speed sensors
• front wheel speed sensor rings
• hydraulic control unit (HCU)
• stability assist module (ECU)
• stability assist event indicator
• lateral accelerometer
• longitudinal accelerometer (4x4)
• rear wheel speed sensors
• rear wheel speed sensor rings
• steering wheel position sensor
• yaw rate sensor
• yellow anti-lock brake warning indicator
• brake pressure transducer
• traction control switch

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I suspect the abs issue is causing the speed control not to work if it happened at the same time the cruise control stopped working. When the yellow ABS light comes on, it means the ABS is dactivated. You may have a faulty accelerometer which senses acceleration and yaw (side to side lean). I have not seen a bad one but you said it is sensitive to acceleration.
I would unplug it and see what happens. The connector should have a small tab to depress so you can pull the connector out.
Here is where it is:

Accelerometer Removal and Installation

1. NOTE: The accelerometer is located under the center, rear passenger seat carpet. (I think you have to remove seat for access).
   Cut the carpeting along the perforations.

1. Disconnect the electrical connector.

1. Remove the nuts and remove the accelerometer.

Have dealer hook up tester and pull fault codes if you can't find an easy solution.
Some background info

A malfunction in the anti-lock brake system will cause the anti-lock brake control module to shut off or inhibit the system. However, normal power-assisted braking remains.

Malfunctions are indicated by the yellow ABS warning indicator in the instrument cluster.

The anti-lock brake system is self-monitoring. When the ignition switch is turned to the RUN position, the anti-lock brake control module will carry out a preliminary self-check on the anti-lock electrical system indicated by a three-second illumination of the yellow ABS warning indicator in the instrument cluster.

During vehicle operation, including normal and anti-lock braking, the anti-lock brake control module monitors all electrical anti-lock functions and some hydraulic operations.

Each time the vehicle is driven, as soon as vehicle speed reaches approximately 20 km/h (12mph), the anti-lock brake control module turns on the pump motor for approximately one-half second. At this time, a mechanical noise may be heard. This is a normal function of the self-check by the anti-lock brake control module.

Pedal pulsation coupled with noise while braking on loose gravel, bumps, wet or snowy roads is normal and indicates correct functioning of the anti-lock brake system.

Warning Lamp Indicator
The anti-lock brake system (ABS) uses the yellow ABS warning indicator to alert the driver of a malfunctions in the ABS.
The yellow ABS warning indicator will come on to warn the driver that the ABS has been turned off due to a symptom that exists in the ABS. Normal power assist braking remains but wheels can lock during a panic stop while the yellow ABS warning indicator is illuminated.

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Please report back, I am curious if that is what it is. Good luck