What Causes the Noise When Auto Hold is Activated?
4 Answers
That is the sound of the parking motor working, not abnormal noise. Here is some relevant information about auto hold: 1. Introduction to Auto Hold: The English name for the auto hold system is AUTO-HOLD. Some car models label the button directly as "AUTO-HOLD" on the vehicle, while others use a pair of semicircles enclosing an "A" inside a circle. Although the styles may vary, the functions implemented by the buttons are the same. 2. Activating Auto Hold: The AUTO-HOLD function is not enabled by default on almost all car models; it requires the driver to manually activate it. After pressing the auto hold function button, every time the vehicle comes to a complete stop by braking, an indicator light will illuminate on the dashboard. At this point, there is no need to press the brake pedal, as the system will automatically complete the braking. When the accelerator pedal is pressed, the system will release, making it very convenient, especially suitable for stop-and-go traffic or when waiting at traffic lights.
I encountered a similar issue when repairing my car recently. When the auto-hold function is activated, abnormal noises often occur, mostly related to the braking system. For example, aging gears or lack of lubrication in the motor-driven brake actuator can cause squeaking sounds. Dust accumulation leading to sensor misjudgment may also trigger irregular friction noises. I recommend first identifying the source of the noise—if it's near the wheels, check for brake pad wear; if it's coming from under the car, it might be loose electronic module connections. Don't forget regular maintenance, cleaning brake components and sensors to prevent dust buildup. I've seen many cases where minor noises were ignored, eventually escalating into major repairs. Safety first—if persistent abnormal noises occur, get a professional diagnosis as soon as possible. Usually, minor adjustments or part replacements can resolve the issue, so don't delay until costs skyrocket.
Once my car made a rattling noise after the auto-hold was activated, which was particularly annoying. After troubleshooting, I found sand stuck in the brake. The sources of abnormal noises are diverse, often caused by mechanical components like dry or worn actuator gears, or electronic units affected by moisture interfering with signals. When the system pressurizes during startup, rainwater or dirt can enter if the seals are compromised. Quick tip: Before driving, simply check the sensor area and keep it dry. If the noise is slight but persistent, don’t panic—most cases can be resolved with simple fixes. If the noise grows louder or is accompanied by vibrations, stop immediately and inspect. Developing these habits can help prevent such issues in advance, saving you from urgent repairs later.
The abnormal noise may indicate that the actuating components require lubrication. When the auto-hold system is engaged, it activates the electric brake actuator. If left unmaintained for an extended period, increased friction between gears can cause noise. Inspect the brake discs and connecting wires for wear or looseness, as metal corrosion during humid seasons often leads to noise. Address the issue promptly to prevent cascading failures, since safe driving is the top priority. Try manually activating the system several times to see if the noise recurs.
