Troubleshooting Electric Parking Brake Problems
Have problems with your Electric Parking Brake? Follow the procedures below to troubleshoot the problems. This guide provides instructions on diagnosing a faulty parking brake actuator without a scanner.
How does an electric parking brake work?
Traditionally, handbrakes or parking brakes consist of cables connected to the brake shoes or disk brakes, giving a decent amount of pressure to lock the wheels when pulled. The cabin side of the parking brake consists of a locking lever and a handle with a release button.
With the advent of technology, electronic handbrakes were invented. These parking brakes work on the same principle as their predecessors, but a push replaces the handbrake lever or pull button. Cables no longer exist and are replaced by wires. The mechanical actuator is replaced with electric motors, which are mechanically linked to the calipers or brake shoes.
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If your car develops symptoms similar to those below, please read our step-by-step guide on diagnosing a bad parking brake actuator.
Symptoms
Common symptoms of faulty parking brake actuators are:
- Flashing parking brake light,
- Message on the dashboard saying that a parking brake service is required.
What you will need
Tools
- Tire wrench
- Jack
- Jack stand
- Multimeter Tester
Procedure
- Park the vehicle on safe and level ground.
- Place wheel chocks on the rear wheels.
- Use a tire wrench to loosen the affected wheel’s lug nuts by turning the wrench counterclockwise.
- Using a jack, hoist the vehicle up and remove the wheel from the affected side using a tire wrench.
- Support the jack with a jack stand.
- Once you find the electrical connector to the caliper, disconnect it for testing. Push the locking tabs and then pull the connector off.
- Check for a power supply for the electric actuator motor. To accomplish this, you need to have a multi-meter tester. Set the multimeter to measure DC or direct current. Look for an icon with one straight line and three small horizontal lines parallel underneath the said straight line. Point the selector to the DC icon. Find the connector that leads to the body or main harness of the wiring. Place the black and red leads on both ends of the said connector.
8. Initially, there should be zero or a very low voltage reading. Have someone start the engine, turn the ignition, and set the parking brake on. If the voltage reading is in the range of 10-12 or -10 to -12 volts, then you have decent power for the actuator. If there is no voltage or the voltage is lower than 10 volts, you should check the wiring or the fuse. Please note that the polarity, in this case, is irrelevant since you can interchange the leads.
- Note: Older multimeter testers have voltage ranges; you may set it to 20 volts or greater. Do not set the voltage to any settings that end with mv; MV means millivolts. Using these settings on a 12-volt system could damage the multimeter.
9. Test actuator solenoid winding for continuity. The next step is to test the actuator winding for damage. You can carry out this task by finding the connector attached to the caliper.
- Check the multimeter set to continuity or ohms; the ohms icon is similar to the omega icon. You should do a multimeter self-test by connecting both leads and setting the beep on; the self-test should result in zero ohms; if the result is greater than zero, there could be a problem with your test leads or multimeter.
- In this case, you should replace your multimeter or leads before doing the test.
- If the self-test is ok, connect both ends of the leads to both ends of the connector.
- If you hear a beep, your actuator winding is good; the problem could be coming from somewhere else, like the switch. But you must replace your actuator solenoid if the beep is not activated.
10. Remove the jack stand.
11. Re-install the tire.
12. Fasten the lug nuts by turning the tire wrench clockwise.
13. Lower the jack and remove it.
14. Fasten the lug nuts.
15. To check the actuator on the other side, repeat steps 1-14.
Troubleshooting Electronic Parking Brakes
The YOUCANIC Full System Scanner is a perfect example of an OBD-II scanner for troubleshooting the electronic parking brake system. This powerful device can read and clear fault codes from all the systems, perform bi-directional tests, maintenance and repair resets, and many more professional-grade functions that can help you determine what is the cause of the problem.
Frequently Asked Questions
What could be the problem if parking brakes actuators are good at the voltage on both caliper terminals?
It could be as simple as a defective parking brake switch, the wiring, or a damaged module.
Is the parking brake a separate braking system?
Parking brakes can also be used if your main braking system fails, so they are also called emergency brakes. They are separate in actuation since they are engaged using electric or mechanical actuators. Still, they use the same braking components, such as brake pads, shoes, calipers, ordrums.
We hope you find the Troubleshooting Electric Parking Brake Problems guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.
