Parking brakes are essential, especially on sloppy inclines, as they prevent your car from slowly moving down the hill. They also prevent your car from reversing while stalled in traffic on a mountain road. As such, fixing any parking brake issues that may arise as soon as possible is critical.
Common Causes of Audi Parking Brake Issues and Potential Fixes
The main cause of Audi parking brake failure is a faulty ECU module. However, a stuck or damaged parking brake switch can sometimes be the main culprit. Other causes of parking brake issues include faulty parking sensors, damaged wiring, low brake fluid, worn-out brake pads, damaged brake calipers, and poor brake calibration.
Low Brake fluid
Sometimes, a parking brake malfunction is caused by a shortage of brake fluid. The lack of brake fluid will cause some of the parking brake components to get stuck, preventing the parking brake from working.
Solution:
- Check the level of fluid in the reservoir. If the brake fluid is low, add more.
How to add brake fluid to your car
- Locate the reservoir first. It is usually located near the firewall on the driver’s side of the engine compartment.
- Remove the cap from the reservoir and pour in the new fluid using a funnel.
- Check the level frequently as you add the brake fluid, and stop when it reaches the required level
- Also check for possible leaks on the seals and change them if they are damaged
Notes:
- If your parking brake is still not working after adding fluid, check to see if the brake fluid is contaminated with dirt and other debris. If this is the case, flush the brake fluid and replace it with a new one.
- Ensure you bleed the brakes after adding fluid to remove any air bubbles that may have been introduced into the system.
- Bleeding the brakes can be difficult, so it is best to have it done by a professional.
Damaged Brake Calipers
The brake calipers aid in stopping the vehicle when you depress the brake pedal. The parking brake will not work if the calipers are damaged.
Solution:
- Inspect the brake calipers and replace them if you can.
- Alternatively, take your car to an Audi-certified professional to inspect and replace your brake calipers.
Worn out Brake Pads
If your parking brake pads are too worn, your parking brakes will not work, and using them will damage them even more.
Solution:
- Inspect your brake pads to determine if they are damaged.
- Clean them if they are still fine but have caked-on debris, which may cause issues.
- If they are worn out, replace them.
How to replace brake pads
- Locate the caliper that holds the pad in place.
- Use a wrench to remove the two bolts holding the caliper.
- Then, carefully remove the old pad and clean the area.
- And then place the new pad in place.
- Line up the holes in the new pad with the bolts in the caliper.
- Then replace the caliper bolts and tighten them.
Note: To avoid damaging the rest of the parking brake system, consider hiring a professional to handle the job.
Faulty Parking Brake Cable
The parking brake cable applies pressure to the pads when you use the parking brake. Over time, the cable can become frayed or damaged, causing it to malfunction. The connectors can also be affected by dirt and debris or become corroded. Additionally, rodents may chew them and damage them.
If the cables are not functioning properly, the parking brake system cannot function either.
Solution:
- Inspect the parking brake cable to assess its condition.
- If the cable is damaged or frayed, replace it.
- If you lack the know-how, let a professional do the replacement, as it is a relatively complicated process.
Faulty Electronic Parking Brake Button
The parking button might become stuck and malfunction if dirt or other materials get inside it. The same thing happens if you spill drinks on the console and the liquid seeps into the button.
Solution:
- Clean the button and use a sharp object to dislodge any debris causing it to stick.
- If this does not work, replace the button and its supporting components.
- Or have a professional do the repair or replacement.
Low/Faulty Battery
Your parking brake motor relies on power from the car’s battery. As such, you cannot release the brake if the car battery dies or only provides minimal voltage.
Solution:
- Reset your battery to see if this will help.
- If it does not work, test the battery charging terminals using a multimeter to see if it is the cause of the issues.
- If this does not work, replace the battery.
How to Do a Battery Reset
Resetting the Audi parking brake can sometimes be done by disconnecting the car’s battery. However, it’s important to note that disconnecting the battery can also reset other systems in the car, so it’s not always the recommended method.
To reset the parking brake by disconnecting the battery, you’ll need to follow these steps:
- Turn off the ignition and remove the key from the switch unless you have a keyless car.
- Locate the car’s battery, use a wrench to loosen the negative battery cable clamp, and remove it from the battery terminal.
- Wait for 10-15 minutes to allow the car’s electronic systems to reset.
- Then reconnect the negative battery cable clamp to the battery terminal and tighten it with the wrench.
Software Issues
If a mistake or bug in the ECU software controls the parking brake, it can cause the brake to engage or disengage incorrectly, leading to malfunctions. This can happen if the software is not properly updated or there is a compatibility issue between different components.
Solution:
- Update the software using certified software updates.
- If you cannot update, go to an authorized Audi dealership or repair shop for assistance.
- Reset the parking brake system.
Note: Ensure any software-related issues are diagnosed and repaired by a qualified mechanic with experience in Audi software.
How to Manually Reset the Parking Brake System
This reset is necessary, especially after replacing brake components such as the brake pads. Here are the steps to reset the parking brake on an Audi:
- Turn on the ignition, but do not start the engine.
- Press down on the brake pedal and hold it down throughout the reset process.
- Press the parking brake switch and hold it until the parking brake light flashes several times.
- Wait until the parking brake light stops flashing and remains illuminated.
- Reactivate the parking brake by long pressing the brake switch until the parking brake light on the dashboard turns off.
- release the foot brake pedal and verify the parking brake is disengaged.
Note: the specific process for resetting the parking brake may vary slightly depending on the Audi model and year. Refer to the vehicle’s owner’s manual or seek professional assistance if unsure.
How to do an OBD Reset
This procedure requires a bit more technical expertise and equipment.
- Connect the diagnostic machine to the Audi’s OBD-II port.
- Turn on the diagnostic machine and follow the instructions to access Audi’s electronic parking brake module.
- Decode fault codes related to the parking brake system to determine the issue and repair or replace the component causing the issue.
- Then clear the fault codes using the diagnostic machine.
- Test the parking brake system to ensure the issue is resolved.
Faulty ECU Module
If Audi’s electronic control unit (ECU) was the source of the parking brake error, you have successfully diagnosed the problem.
Solution:
- Recalibrate the ECU module. Download the calibration file from the Audi website and follow the installation instructions.
- If this does not work, replace the ECU. You can purchase a new ECU from Audi or a third-party supplier.
- If the problem persists, taking the car to an Audi dealership for servicing may be necessary.
Fault Wheel Speed Sensors
The wheel speed sensor, sometimes called an ABS sensor or an ABS brake sensor, is essential to your braking system. The ABS receives information from the speed sensor and tone wheel about the speed of your vehicle’s wheels.
A faulty wheel speed sensor can cause the parking brake to malfunction, as the ECM may not receive accurate information about the wheel speed. This can cause the parking brake to fail to engage or disengage properly, resulting in potentially hazardous situations.
Solution:
- Inspect the wheel speed sensors and replace them if they are damaged.
Fault Parking Sensors
If the parking sensors are not working, they do not connect with the parking brake when the driver clicks the parking button. The parking brake may not release when the driver presses down on the pedal.
This can lead to your car rolling away unexpectedly or getting stuck in park mode.
Solution:
Take your vehicle to an auto shop to replace the parking brake sensors. This process is complicated and better handled by a professional to avoid damaging other brake system components.