Everything else is running fine at 154,000 miles.
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.
FOR ONE THING CHANGE MECHANICS ! HE SHOULD HAVE FIXED THE PROBLEM, YOU MAY HAVE A SERIOUS BRAKE ISSUE ! IF LIGHT IS ON IT WILL NOT PASS INSPECTION ! YOU MAY HAVE AIR IN SYSTEM, NEEDS BLEED ! FLUID COULD BE CONTAMINATED , NEEDS BLEED OUT, REPLACED W/ FRESH FLUID ! ABS REQUIRES THAT THE REAR BRAKE CIRCUIT OPERATES BEFORE THE FRONT BRAKES, THIS PREVENTS SKIDDING, THE PURPOSE OF ABS BRAKES, CORRECT ? MASTER CYLINDER HAS SEALS, CONTAMINATED FLUID AFFECTS SEALS, BRAKE LIGHT WILL STAY ON UNTIL PROBLEM IS RESOLVED !!! REAR BRAKES IF SHOES NEED ADJUSTED, CLOSER TO DRUM ! THIS WILL HELP, BUT BLEEDING OUT ALL BAD FLUID & AIR IN SYSTEM IS PARAMOUNT !!!!!! BRAKE LIGHT SWITCH MAY NEED REPLACED, PROPORTIONING VALVE WHICH SEPARATES FRONT FROM REAR BRAKES , IS OUT OF BALANCE, THE VALVE NEEDS TO BE @ A NEUTRAL OR CENTERED POSITION, COULD BE STUCK TOWARD EITHER BRAKE CIRCUIT, MORE FRONT THAN REAR, UNDERSTAND ? THINK I COVERED YOUR ISSUE, PLEASE RATE MAY ANSWER ! THANKYOU,
SOURCE: ABS and brake warning light is on
it could be that the wheel sensor is either defective or it is not close enough to the rotor to read. if your not having a issue with braking under driving conditions i would jack the vehicles wheels off the ground and remove them then take brake clean and spray the sensor pick ups to remove any dirt or brake dust. also make sure that the plugs and wires to the sending units are ok also they should be no more than .050 of an inch away from the rotor you can use a feeler gauge to check this. please rate this
SOURCE: 2001 Jimmy ABS and brakes lights came on
I hate to say it, but the abs control module might have died on you. Thats the boxy looking thing under the hood that has a lot of brake lines and wire connectors going into it. I have seen this happen before and it ended up being one of the speed sensors on the wheels but usually its the module. Take the truck somewhere to get the light scanned, and that will give you a better idea of what it is.
SOURCE: no brake lights or backup lights
Did you check the back-up switch on the tranny, or the grounds??
SOURCE: What are probable causes for an ABS warning light
The ABS system has no effect at all on normal driving or braking. There are many problems that will cause a warning. You could have a bad sensor at the rotors or low pressure at the accumulator. You should have the car checked by a mechanic since it is likely that the ABS will not work in a panic stop or in a slippery road condition though you will still have regular braking.
SOURCE: several warning lights come on
You could check if you have front wheel speed sensors. they should be located in the front hub assembley, check for wires running along control arm. Additionally, the two first warning are refer at ABS Module, so, I suggest scanned to know exaclty which fault code is stored there. Some Autozone or AutoShop with reader codes scanner could make it.
How old is your battery? Some vehicles turn on this dash lights when this occurs and its time to new battery; if this its thru... don't forget that our vehicles disable the charging system for a few seconds until the idle stabilizes in cold weather. What this means is that a marginal battery may provide JUST enough juice to start the vehicle but not enough to keep it reading all the inputs and outputs from the PCM, TCCM and EBCM. It then throws multiple trouble codes.
It's simple to have a battery load-tested. (Usually free at any battery dealer.) You cannot tell the state of a battery by a simple voltage test; it must be load-tested.
Now, about heater/defrost, I suggest check the blower fuse, then the blower resistor pack if you've got the manual controls, then the blower motor itself. If you've got the digital controls, check the fuse and the blower first. If those are good, it's probably time to replace the control module.
If your blower only failed to work at the time of the indicator light flakeout, it's most likely the effect of the power being held back from other systems in order to allow for starting. If that's the case, it doesn't come back immediately after the truck starts. There's a lag while the charging system takes over and the PCM can allocate power to those additional sytems.
Additionally, I found this article and you could visit your dealer and ask about this TSB... I don't understand it all, but it does point to the problem: bad ignition switch.
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Subject: ABS Red Brake SVC And 4WD Light On HVAC Blower Inoperative - keywords B1375 C0379 DTC HI4 ignition IPC L04 MIL on U1000 U1041 PIT3832C (12/04/2007)
Models:
2004-2007 Buick Rainier,
2002-2008 Chevrolet Trailblazer models,
2002-2008 GMC Envoy models,
2002-2004 Oldsmobile Bravada
This PI was superseded to update Recommendation/Instructions and model years. Please discard PIT3832B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s).
Condition/Concern:
Vehicle may exhibit a combination or all of the following symptoms: ABS light on, Red BRAKE light on, Service 4WD light on, HVAC blower motor inoperative. Various DTCs may also be present.
Recommendation/Instructions:
Diagnose for loss of battery voltage to the rear fuse block on circuit 300 ORN for the following fuses:
Note: Prior to proceeding forward with the information below, it is important to verify the voltage as indicated however it is equally important to verify the integrity of each circuit. This can be achieved by performing a voltage drop test or by adding a device to each circuit that will supply sufficient load to verify the circuits integrity.
HVAC 30A, 4WD 15A, HVAC 1 10A, BRAKE 10A, TBC RUN 3A.
Check circuit 300 ORN for battery voltage when the ignition key is in the RUN position.
Check for battery voltage at the rear fuse block under the rear seat Connector C1 pin D9.
If battery voltage IS NOT present at these locations, check for voltage at the ignition switch pin G for circuit 300 ORN.
If battery voltage IS present at the ignition switch pin G, check circuit 300 for an open.
If battery voltage IS NOT present at the ignition switch pin G, replace the ignition switch. Note: This PI does not apply to the Saab 97x. The 97x has a unique ignition switch location and an electrical harness. With this new switch, the electrical center pin designations and the ignition switch connector is different. In the event the concern above is experienced in a Saab 97x, circuit 300 can be checked for integrity using the appropriate schematics in eSI. Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
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Keep us updated
ABS LIGHT AND MODULE TROUBLESHOOTING:
Anti
lock brake system light comes up when there is issue with car brake systems. It
can be low brake fluid or faulty ABS fuse or its issue with brake system or assembly.
Your vehicles brake system needs inspection.
To
troubleshoot these issues, I suggest you to refer the help links provided below.
There are direct links with accurate solution, for these specific issues.
Click
the link below and follow the procedure: ------
http://howtobyme.blogspot.com/2011/11/abs-and-service-light-comes-on.html
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http://howtobyme.blogspot.com/2011/11/abs-light-stays-on-but-brakes-work-fine.html
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http://schematicsdiagram.blogspot.com/2011/06/abs-and-traction-control-lights-stays.html
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http://howtobyme.blogspot.com/2011/11/abs-brake-lights-warning-indicator.html
-----------------------
http://whoisbyme.blogspot.in/2012/07/battery-light-and-abs-light-on-dash.html
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http://technoanswers.blogspot.com/2011/11/how-anti-lock-brakes-work.html
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http://technoanswers.blogspot.com/2011/11/brake-system-troubleshooting.html
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http://technoanswers.blogspot.com/2012/01/anti-lock-brake-light-stays-on-all-time.html
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ABS
light comes on and Car makes Grinding noise?
http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html
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http://repairhelpcenter.blogspot.com/2011/11/abs-trouble-codes-for-all-1994-00-acura.html
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http://technoanswers.blogspot.in/2012/05/2008-toyota-highlander-abs-warning.html
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http://technoanswers.blogspot.in/2012/04/2003-lexus-es-vsc-trac-off-abs-lights.html
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http://technoanswers.blogspot.in/2012/04/2008-toyota-highlander-hybrid-warning.html
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http://schematicsdiagram.blogspot.com/2011/12/abs-brake-warning-lights-remains-steady.html
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http://schematicsdiagram.blogspot.in/2012/02/can-i-drive-car-without-abs-fuse.html
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http://schematicsdiagram.blogspot.com/2011/12/where-is-abstcs-module-located-on-2005.html
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http://schematicsdiagram.blogspot.com/2012/01/abs-motor-keeps-running.html
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http://howtobyme.blogspot.com/2011/12/when-car-stopsabs-pump-turns-on.html
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http://technoanswers.blogspot.in/2012/02/replacing-abs-unit-on-buick-century.html
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--------------
http://technoanswers.blogspot.in/2012/04/toyota-camry-premature-abs-actuation.html
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How to replace ABS Modulator Control
Unit on Acura Integra?
http://repairhelpcenter.blogspot.in/2011/11/how-to-replace-abs-modulator-control.html
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How to replace ABS Pump Assembly on
Acura Integra?
http://repairhelpcenter.blogspot.in/2011/11/how-to-replace-abs-pump-assembly-on.html
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How to remove ABS Accumulator on
Acura Integra?
http://repairhelpcenter.blogspot.in/2011/11/how-to-remove-abs-accumulator-on-acura.html
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How to remove ABS Control Unit on
Acura Integra?
http://repairhelpcenter.blogspot.in/2011/11/how-to-remove-abs-control-unit-on-acura.html
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These details will help.
Thanks.
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