The advent of electronic parking brake (EPB) systems offers advanced technology but can pose challenges for the service technician. This article explains the current systems and provides insight regarding understanding and troubleshooting these non-mechanical approaches.
The use of an electric park brake ( EPB ) system is not modern. It ’ second been on some vehicles since the late 1990s, but there seems to be a billow to move to the EPB organization on many raw models .
One major cosmopolitan brake supplier has now produced over sixty million caliper-integrated EPB units ( the park brake centrifugal is depart of the caliper ) and has moved on to their fifth generation of EPB designed products. It is tied showing up on popular tone arm truck models.
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EPB eliminates the mechanical connection between the operator and the park brakes ; it ’ second now operated by wire. The system uses an electric substitution to activate and deactivate the park brakes .
The EPB organization requires an electronic control unit ( ECU ) .
Some earlier versions had a stand-alone ECU, but most of today ’ s versions of the EPB system are about constantly integrated into the vehicle ’ s accountant area network ( CAN ) architecture. This provides the EPB organization the ability to use and share information from the other modules on board for a multitude of functions .
The reasons behind EPB and the two common designs
There are two common designs used in the EPB system : the cable puller arrangement and the caliper-integrated system. It is important to note that neither system will function if there is no vehicle office .
The cable puller design motorizes the traditional handbrake or parking brake bicycle function by using a bidirectional drive. This bidirectional motive supplies the pulling force to the brake cables that run to either the rear calipers or the park brake shoes ( a drum-in-hat rotor vogue ) .
The advantage of this style of EPB system is that it lends itself to be an accessory solution, using some existing parts. Existing cable vogue brake calipers or parking brake shoes can easily be adapted to use the cable puller EPB .
The CAN connected cable puller EPB controller/actuator can be tucked somewhere under the car or even in the torso. Many of the beginning designed cable puller units provided some form of manual free mechanism in the event of a motive failure. Some manufacturers provided access ports and in some cases tools to release the cables .
For exercise, Range Rover had a special cable acquittance under the center console. The cable puller design has been popular and is calm being used, but the caliper-integrated purpose has gained popularity and its simplicity will likely make it the front-runner .
The caliper-integrated design incorporates a bidirectional electric motor on each caliper. This electric motor mechanically forces the caliper piston out to provide the necessary clamp impel on the rotor. Most systems will use a gear reduction driveway to provide the needed force with a small electric motive .
There are respective advantages to the caliper- incorporate EPB design setup. It eliminates the need for brake cables and the hardware and packaging they require. Another advantage is that the fomite manufacture process is streamlined requiring only one hydraulic and one electric connection on each rear-brake fabrication. An add advantage is weight unit reduction .
One manufacturer claims it saves adenine much as 16 pounds on a life-size SUV/pickup. Reducing vehicle burden, reduced emissions and increasing fuel economy is a common subject in today ’ s automotive global .
The will be CAN network, allowing consolidation into other on-board systems. The caliper-integrated EPB system is normally used on Volvo, VW, Audi, Ford F-150, Honda and many others .
Space save is another advantage to the EPB arrangement. The area that was devoted to a pedal point assembly or a park brake cover unit in the traditional hunch area, foot well, and center consoles, can now be used for other things .
Some manufacturers claim there ’ randomness increased resident safety by the removal of the wield or pedal assemblies during a collision. But the gains in safety don ’ deoxythymidine monophosphate good stop there .
It can function completely automatically ( without driver input signal ), applying and releasing the park brakes as needed when the transmittance is put in parking lot or, in a vehicle with standard transmission, when the key is turned to the off stead. It can apply the park brake if the driver ’ mho doorway is opened, if the driver ’ s seat belt is undo, or if the torso or hood is opened. It can besides be used as a hill holder to prevent the car from rolling back at a stop consonant sign .
furthermore, it can be incorporated with the anti-lock brake system ( ABS ) to provide low-speed traction operate, or be used as an immobilizer, locking the wheels when the fomite is parked, and the ignition is off .
And in the event of a hydraulic brake failure, it can bring the fomite to a stop — much like an ABS catch — without the rear wheels locking improving and causing a spin-out. The EPB could besides be tied into the rise backup television camera and apply the brake if the camera detects an obstacle .
In both designs, the EPB faculty will control the action of the bidirectional cable centrifugal or caliper motors that apply the clamp violence. The EPB faculty will monitor specific aspects of its own system, including the gape rate of the fomite, the position of the EPB switch, and the clamping wedge that is being applied to the brake cables or caliper pistons ( typically using the amperage that the enforce motors are consuming ). It can besides monitor the temperature of the clamp motors and manipulate unit .
The EPB organization besides will perform self-diagnostics and will set and record trouble oneself codes if it sees a problem. Codes can be set for any issue of reasons, including overheated motors, shorts, opens, unintentional grounds, communication errors. This information besides aids in diagnostics .
EPB provides a dependable and more accurate park bracken system and while servicing them involves learning a few new tricks, it ’ s not excessively intimidating .
Proper up-to-date and valid serve information is vital for proper and safe repairs of the EPB system. Vehicles equipped with EPB may experience unexpected parking brake application, which could result in personal injury and system damage. The EPB system must be in overhaul or maintenance mode anterior to servicing or removing rise bracken components .
Cable puller EPB system tricks
Performing certain brake services will depend on the EPB system you are dealing with .
rear bracken pad service or evening caliper successor on GM ’ mho Chevy and Cadillac models with the cable puller EPB system is performed similar to a non-powered park brake system. But if any parking brake cable or EPB unit surrogate is required, the EPB will need to be put into service mood .
This can be done manually using the service port on the EPB faculty and backing the motor off by pass, using the proper cock. Don ’ deoxythymidine monophosphate be tempted to use a power cock, as it may cause price to the EPB unit. A scan tool may besides be used to get the EPB assembly into serve mode and is the favored method. But after the cables are replaced, the EPB needs to be tensioned and this can merely be done using a scan tool following the specific reset calibration routine .
Lexus has a like manual release procedure available for their cable puller design, but again after the service exercise has been performed, a scan tool that will communicate bidirectional with the EPB module is going to be needed to finish the animate, and turn off the EPB light .
The BMW 750LI ( other BMW models besides use a cable puller design and the EPB unit is mounted under the rear cargo area ) uses a cable puller EPB and the module is in the luggage compartment. If anything gets spilled or the trunk has a urine escape, the EPB module is in the low spot and can be damaged. This water intrusion can cause the EPB faculty to freeze, seize up or turn on the EPB light .
The BMW creature kit does supply the instrument needed to manually release the EPB if it will move ( they are normally seized solid ) and the owner ’ s manual explains how to perform a manual of arms exhaust .
These BMW EPB motors besides have a set of plastic gears that go bad and tire to look like an apple core. They are not available from BMW, but surrogate gears are available on-line. The cost savings is substantial when the accomplished unit that the dealer will supply is more than $ 1,000. The EPB unit of measurement can be re-initialized manually after gear successor by pressing the parking brake button three times with five-second intervals between pushes. The motor will try to release the brakes, then apply the brakes and ultimately release the brakes to complete the low-level formatting. A BMW-compatible scanner besides can be used .
Integrated EPB system caliper servicing tricks
Using a scan tool is typically going to be the manufacturer ’ s recommended method to retract the calipers to their service status to allow rear brake service or embroider replacement. The scan cock is then used again to exit the service mode and automatically adjust the pads to the right clearance after the raise brake avail is performed .
But there are several makes and models that let maintenance or service mode to be reached without a scan instrument .
Ford integrated EPB system caliper servicing without a scan tool
EPB Service mode or EPB care mode can be entered on the 2016 F-150 or the 2015 Ford Fusion loanblend using the play along routine without a scan tool .
To enter serve modality :
1. Place the ignition trade to the ON placement ( engine off ) .
2. depress and hold the catalyst pedal to the floor while holding the EPB switch in the acquittance position. Continue to hold the catalyst pedal and EPB switch over .
3. Turn the ignition switch to the OFF position and then return it to the ON put within five seconds while continuing to hold the catalyst pedal and the EPB switch over .
4. At this charge the EPB system will be in service manner. The yellow EPB index will be illuminated on the dash and the Maintenance Mode warn will show on the message center .
note : When the organization is in service mode, the park brakes will not function until the manner has been deactivated .
1. Turn the ignition OFF and release both the accelerator pedal and the EPB trade .
2. Perform the need rear brake service. The Ford caliper piston does not have to be rotated back into the caliper, but does need to be compressed using the proper tool. The practice of a C-clamp or pliers may damage the caliper or drive, so they aren ’ metric ton recommended .
Exiting military service manner, after the repairs are made :
1.Place the ignition switch to the ON status ( engine off ) .
2. depress and hold the accelerator pedal to the floor while holding the EPB switch to the give position. Continue to hold the accelerator pedal and EPB switch .
3. Turn the ignition switch to the OFF position and then return it to the ON position within five seconds while continuing to hold the accelerator pedal point and the EPB switch.
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4. The EPB system will apply the park brake and release it into the proper position .
5. Release the accelerator pedal and the EPB switch .
Dodge/Jeep integrated EPB system caliper servicing without a scan tool
The EPB service modality can be entered following the menu driven instructions on the Uconnect driver ’ s information screen on some Dodge, Chrysler and Jeep models equipped with the integrated EPB system. You enter the brakes area from the settings blind and just follow the on-screen instructions. After the repair is completed, the overhaul mode must be exited again using the Uconnect screen ( a scan instrument can be used a well ) .
Honda integrated EPB system caliper servicing without a scan tool
Honda is using an EPB-integrated caliper on some of their newer models. A scan joyride is the prefer method acting of retracting the rear calipers for serve, but they besides have a factory recommended method if the allow scan creature international relations and security network ’ metric ton available .
The factory serve manual instructs you to :
1. Turn the key to the OFF place .
2. Remove the two bolts retaining the electric park brake actuator from the back of the caliper fabrication .
3. Using a T45 Torx driver, turn the spindle shaft on the caliper 360 degrees clockwise to release the parking brake. Make certain the parking brake is released, and if not, repeat the turn of the worm gearing cheat 360 degrees .
4. Remove the caliper and using a compressor, press the piston straight back ( turning is not required ) .
5. After the back bracken service is complete, reinstall the electric parking bracken actuator, using a new sealing O-ring and screws, making sure the felt open is fairly .
6. Turn the key to the ON position .
7. Pull the EPB switch to the on military position to apply the park brakes and push on the brake pedal at the same clock time. This will exit brake pad maintenance mode .
8. Turn the ignition off .
Mazda integrated EPB system caliper servicing without a scan tool
Mazda provides a non-scan creature choice for 2016/2017 CX-5s to retract the integrated caliper back for service, that is very exchangeable to the procedure for Fords. This routine can be followed to enter maintenance mood .
Entering service mode :
1. Switch the ignition ON, and don ’ t touch the bracken pedal ( the engine must be off throughout the operation ) .
2. Release the EPB. Note Steps 3 and 4 must be done within five seconds .
3. While simultaneously pressing the accelerator pedal down in full, and pressing the EPB switch over and holding both, switch the ignition OFF. You need to hold both the accelerator and EPB switch in this put during the next pace .
4. Switch the ignition ON, while maintaining the depressed bicycle and EPB switch .
5. If you have done everything correctly you should hear the caliper motors retracting. The yellow park brake symbol with exclamation point will now be illuminated, indicating you are immediately in alimony mode .
6. Switch the ignition off .
note : Mazda does not want the piston rotated when servicing the caliper, merely pushed back. Rotating the piston may damage the caliper inner parts .
Exiting service manner :
1. Switch ignition ON, engine off. Note Steps 2 and 3 must be done within 5 seconds .
2. While simultaneously pressing the accelerator pedal down fully, and pressing the EPB switch and hold, switch the ignition OFF. You need to hold both the accelerator and EPB switch over in this position during the adjacent step .
3. Switch the ignition ON, while maintaining the press down pedal and EPB trade .
4. You should hear the caliper motors performing the automatic adaptation and the yellow warn light should go out, indicating alimony mode has ended .
5. Switch the ignition OFF .
Other EPB tips and tricks
If working on some models of VW/Audi with an integrated EPB, not merely will you need a scan cock to put the calipers into service mode and then re-initialize them, but you may besides need to enter the actual brake pad material thickness .
The EPB system will use an algorithm to calculate the wear on the rear brake pads. This replaces the necessitate for a embroider wear detector. evening if you have done the pad refilling by rights, the brake wear admonitory fall may stay on and trouble codes may be introduce until this brake pad thickness information is set into the EPB module. so, make a flying measurement of the pad thickness just in lawsuit you need this information .
many EPB-equipped vehicles need software updates to fix issues that could cause either the EPB to stick, drag, not release, or illuminate the EPB light. GM ’ s Impala, some Cadillac models, Subarus and some Jeep Renegades have TSBs for reflashes and software updates. These updates correct different EPB issues from false applications to brake drag .
Honda has a hark back to eliminate an publish that will cause the rear brakes to drag on some EPB-equipped Civics, and the situate is a software update .
Mazda ’ second besides has a recall on its EPB organization. A seal return on the raise integrated caliper design may allow urine to enter, causing corrosion. This corrosion can cause the caliper to jam or fail to properly engage .
Some Jeep Renegade models have the EPB module located in the left rear cargo area and water could enter the faculty or the connection. This can cause the EPB not to release or result in service light concerns .
Bring this to a stop
Yes, a scan cock is going to be the manufacturer ’ randomness recommended method for repair or service, but many manufacturers provide a non-scan creature overhaul mode, with the Fiat/Chrysler process by far the easiest .
A scan instrument will be required for diagnostics, but most good scan tools can perform the needed tasks .
Reflashing the EPB software is a different narrative and may need consecrated manufacturer ’ sulfur equipment and services .
Most technical school will agree that working with an EPB-integrated caliper design is easier to service without a parking brake cable, and that ’ s something that most techs will embrace. ■
Jeff Taylor boasts a 32-year career in the automotive diligence with Eccles Auto Service in Dundas, Ontario, as a in full licensed professional lead technician. While continuing to be “ on the bench ” every day, Taylor is besides heavily involved in government focus groups, serves as an accomplished technical writer and has competed in external diagnostic competitions american samoa well as providing his expertness as an automotive technical teacher for a major aftermarket parts retailer .
See more of Jeff Taylor’s articles here:
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