Is the ticking sound when starting the new A6 the ABS working sound?
4 Answers
When starting the new A6, there is a ticking sound, which is the working sound of the ABS. It is the sound of the automatic parking function releasing the brake. Introduction to car ABS: Car ABS is an anti-lock braking system. The working principle of the braking system is to use the mutual friction between the non-rotating elements connected to the body (or frame) and the rotating elements connected to the wheels (or drive shaft) to prevent the rotation or tendency of rotation of the wheels. The role of ABS: ABS automatically controls the braking force of the brake during car braking, preventing the wheels from locking up and keeping them in a state of rolling and sliding, ensuring that the adhesion between the wheels and the ground is at its maximum. During braking, ABS quickly determines the wheel lock-up state based on the speed signals from each wheel speed sensor, closes the normally open input solenoid valve on the wheel that begins to lock up, and keeps the braking force unchanged.
My A6 is only three months old, and it always makes a ticking sound when starting. At first, I also thought it was an ABS issue. Later, I specifically went to the dealership to ask the technician. They said new cars have many electronic systems, and each startup involves a self-check procedure. The ABS pump briefly powers on for testing during this time, similar to the 'click' sound when turning on household appliances—it’s not a fault signal. I’ve observed the pattern: the sound always occurs once during a cold start, but not when starting in traffic jams. The technician even taught me a simple way to verify it—lightly resting my foot on the brake pedal, I could feel a slight vibration. If the sound suddenly becomes continuous or includes noise, that’s when it’s time for a check-up. Of course, the tire pressure monitoring system disengaging or the electronic parking brake releasing can also make occasional sounds, but they’re different from this ticking noise.
Having repaired Audis for 15 years, I've seen countless cases of A6 starting noises. That ticking sound is mostly the ABS solenoid valve resetting, especially noticeable during auto start-stop activation. There are two reasons: first, German cars' electronic systems perform startup self-checks, causing the ABS pump relay to engage briefly; second, there's a metal reset sound when solenoids wake from sleep mode. It's very different from actual ABS activation - during normal operation you'll hear rapid 'click-click-click' sounds with brake vibration, and it only triggers during hard braking in rain. Try disabling auto start-stop - if the noise disappears, that confirms it. But note: if accompanied by heavy steering or warning lights, it might be a steering gear hydraulic valve issue requiring diagnostic trouble code reading.
Last week, I accompanied my best friend to pick up her new A6, and she was also startled by the ticking sound during startup. The salesperson explained that it's a normal phenomenon, similar to the sound of a computer's fan spinning up when booting. I checked the manual—the electronic parking brake makes a 'click' when releasing, but it's different from the ABS self-test tone (the ABS sound is crisper, like pressing a ballpoint pen). Three things to note: sound frequency (normally only once), temperature effects (more noticeable in winter), and driving conditions (might not occur when starting on a slope). If still unsure, have the service center run an OBD scan—no issues if the ABS system shows no error codes starting with 'C.' Honestly, high-end cars nowadays have too many electronic sounds—even the reversing radar beeps come in three different rhythms.
