Electronic parking brake: What to know

Auto manufacturers strive to please customers with easier ways to drive, one such recent times advance is the electronic/electric parking brake (EPB). Most modern cars have incorporated EPB. Electronic parking brakes first appeared on BMW’s 7 Series (E65) in the year 2001.

In this article, we’ll discuss the functions of the electronic parking brake, how it works, the advantages, challenges, and how it relates to tyres. Sit back and enjoy the read.

What is an Electronic parking brake?

Electronic parking brake button (photo: BMW AG)

Electronic parking brake, popularly abbreviated as EPB is also referred to as electronically controlled emergency brake. It is an electronically controlled parking brake.

How it works

EPB is activated by pulling up the EPB button and deactivated by pressing the button downwards, all this while depressing the brake pedal. The holding mechanism uses an electronic control unit (ECU) and an actuator to apply the rear brake. Some automobiles have automatic release function where the EPB is deactivated by belting up and slightly pressing the accelerator pedal while on “D”, while the engine is idling.

Two EPB actuation mechanisms are currently in use; caliper integrated system and cable puller system. Electronic parking brakes can be considered as a subset of brake-by-wire technology.

Audi’s caliper integrated EPB (photo: Audi AG)

Uses of Electronic Parking Brake

Just like the traditional handbrake, electronic parking brake is used to secure a parked vehicle such that it wont roll from the point of parking. Secondly, it is used to bring a moving vehicle to a halt in an emergency situation i.e. brake failure. Activating the EPB while moving will gradually brake the rear wheels safely using the ABS system to avoid skids that would otherwise render the car uncontrollable.

Most common electronic parking brake challenges

Like every electronic system and component in a vehicle, problems can occur on the EPB if switches or wires between the actuator and module are opened, shortened, broken, or develop high resistance. Common issues such as low system voltage or open fuse can cause the electronic parking brake system to malfunction.

Most of these faults will register a trouble code on the onboard computer, indicating a fault with the EPB, or display a ‘Service parking brake’ message if there’s a reported fault. A scan tool will help track down the cause of the failure.

In any case, if the issue is a result of a failed module, you will have to order a replacement from auto spare dealers. These components are relatively new, and they have not saturated the market. However, as time goes on, these components will be available in many autospare shops.

Most automobile manufacturers provide for a manual way of dis-engaging the EPB in case of a severe electronic system malfunction.

Advantages of electronic parking brakes

  1. Automation i.e hill-hold and start, hands-free release as you drive off.
  2. A growing number users consider EPB safer and better compared to traditional handbrake for emergency braking.
  3. Occupies less space and saves on weight.
  4. Child lock system: – You can’t operate the EPB while the ignition is off.
  5. Minimal physical effort hence ideal for physically challenged drivers.

Final word

The electronic parking brake is a welcome invention in modern cars for safer emergency braking over conventional handbrakes, mostly at high speeds. However to increase your chances of stopping in an emergency braking, you need to have emergency brake-able tyres especially at the rear. However, just like everything good, there is a price to pay, be prepared for the challenges that come with this smart car invention.

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