VW Caddy: Spongy Brake Pedal Signals System Problems

Experienced similar issues with my 2019 VW T-Cross 1.5 TSI last winter. As someone with moderate experience working on cars, I initially thought it was related to the brake calipers or hydraulic brakes system. After checking the brake fluid (which was fine), I took it to a workshop since the symptoms were getting worse. Turns out the problem wasnt actually with the metal brakes or disc brakes, but rather an electrical issue causing undervoltage in the brake control module. The repair included: Full diagnostic scan, Cleaning electrical connections, Replacing a faulty voltage regulator, System recalibration Total cost was 240€ and completely resolved the spongy pedal feel and vibrations. Before suggesting specific solutions, could you share: Does the issue occur when the engine is cold or warm? Are there any warning lights on the dashboard? Have you noticed any changes in battery performance? When was your last brake service? These details would help determine if youre facing the same electrical issue or if its actually related to your brake system components.

Thanks for the detailed response regarding the potential electrical issue. My last service was at 20000km, about two months ago, where they performed a standard inspection including brake system check. No warning lights are showing on the dashboard, and the issue occurs regardless of engine temperature. The spongy pedal feeling has become more noticeable over the past week, especially during city driving when the brake pads get more use. The vibration through the brake pedal seems to worsen during moderate to heavy braking. I checked the brake fluid level yesterday and it appears normal, with no visible leaks around the brake calipers or lines. Based on your experience, would you recommend still checking the electrical system even though there are no battery or electrical symptoms?

Thanks for those additional details about your Caddy. While my T-Cross issue was electrical, your symptoms sound more like a mechanical problem with the brake system, especially since its getting worse with city driving and heavy braking. The increasing sponginess in the brake pedal, despite normal brake fluid levels, could indicate air in the brake lines or wearing brake pads. Since your car was serviced recently, ask the workshop to specifically check: Air bubbles in the brake system (might need bleeding), Brake pad thickness (uneven wear can cause vibration), Brake caliper movement (could be sticking) Unlike my electrical issue, your symptoms match classic brake system problems. I paid 240€ for my electrical fix, but basic brake system maintenance like bleeding or pad replacement typically costs between 150-300€ depending on what they find. While my electrical problem showed immediate improvement after the fix, brake system issues tend to worsen gradually. Since youre experiencing progressive deterioration, Id recommend getting it checked soon rather than waiting for more serious symptoms to develop. Would you be able to describe the exact feeling when you press the brake pedal? Does it take more pressure than usual to achieve normal braking?

The brake pedal definitely requires more pressure than usual to get normal braking performance. When first pressing the pedal, it feels soft and travels further down before engaging the brakes effectively. During moderate braking, there's a subtle pulsing sensation that wasn't present before. Given your feedback about mechanical vs electrical issues, I agree it sounds more like a hydraulic brakes problem. The symptoms match what you described about potential air in the brake lines or worn brake pads. Since the vibration is most noticeable during heavier braking, I suspect the disc brakes might also need inspection. I will contact the workshop that did my recent service to have them specifically check the points you mentioned. The progressive nature of the problem does suggest its getting worse, so better to address it now before it becomes a safety concern. Thanks for helping me understand the likely causes. The cost range you provided for brake system maintenance seems reasonable compared to potentially larger repairs if left unchecked. I will update once I get a proper diagnosis from the workshop.