The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2016 Model S Reduced Regen and Soft Brake Pedal

0

Melissa G. · rep 0 · May 22, 5:23 AM · 1 replies · solved · Question

Vehicle: 2016 Tesla Model S 75D

Hi all,

I've been noticing a significant reduction in regenerative braking on my 2016 Tesla Model S 75D lately. It feels like the car isn't slowing down as much when I lift off the accelerator, and I have to use the friction brakes more often. This started a few weeks ago.

Compounding this, the actual brake pedal feels a bit softer than usual, and I have to press it further to get the same stopping power. There are no warning lights on the dash, but the driving experience is definitely different. I'm in a colder climate now, but this wasn't an issue last winter.

Could these two issues be related? What should I be looking for?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 5:23 AM

0

ClearTheCode admin answer:

Reduced regenerative braking and a soft brake pedal on your 2016 Tesla Model S 75D can be concerning, but they are often related to a few common factors. Here's what to consider:

  1. Reduced Regenerative Braking Causes:

    • Battery Temperature: This is the most common reason. Cold battery temperatures significantly limit regenerative braking to protect the battery. While you mentioned a colder climate, if the battery isn't preconditioned or has been sitting, regen will be reduced. This usually resolves as the battery warms up during driving.
    • High State of Charge (SoC): If your battery is nearly full (e.g., above 90-95%), the car will limit regen because there's less capacity to store the regenerated energy.
    • Brake System Health: While less common for just regen, issues with the brake system (like low fluid or a fault) could theoretically have an indirect effect, though Tesla's system is designed to prioritize friction brakes if regen is limited.

  2. Soft Brake Pedal Causes:

    • Low Brake Fluid: A low brake fluid level can lead to a spongy or soft pedal. Check the reservoir under the frunk. This could indicate a leak.
    • Air in the Brake Lines: If air enters the hydraulic system, it can be compressed, leading to a soft pedal feel. This often requires bleeding the brakes.
    • Worn Brake Components: While less likely to cause a soft pedal, severely worn pads or rotors can change pedal feel. However, a soft pedal is more indicative of a hydraulic issue.
    • Brake Booster/Vacuum Pump Issue: Teslas use an electric vacuum pump for brake assist. A fault in this system could lead to reduced assist and a harder-to-press pedal, but sometimes it can manifest as an inconsistent feel.

  3. When to See a Shop:

    • Immediately: A soft brake pedal or reduced stopping power is a critical safety concern. Do not delay. Schedule service with Tesla or a qualified independent shop specializing in EVs immediately. Driving with compromised brakes is extremely dangerous.
    • Diagnostics: A technician will inspect brake fluid levels, check for leaks, test the brake booster, and potentially bleed the brake lines. They will also check for any internal Tesla diagnostic codes related to the braking system, which would be more specific than generic OBD-II codes.
Menu

Help & account