The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2017 Model S - Reduced Regen Braking & ABS/Traction Control Light

0

Ryan M. · rep 0 · May 22, 5:23 AM · 1 replies · solved · Question

Vehicle: 2017 Tesla Model S 75D

Hi everyone, I'm having an issue with my 2017 Tesla Model S 75D. For the past few days, I've noticed a significant reduction in my regenerative braking capability. It feels like the car isn't slowing down as much as it used to when I lift off the accelerator.

To make things more concerning, the ABS warning light and the Traction Control light have both come on in the instrument cluster. I've tried restarting the car a couple of times, but the lights persist, and the regen braking is still weak.

I'm worried this might be a serious issue. Has anyone experienced this combination of symptoms? What should I be looking for? Is there a common sensor or module that could cause both reduced regen and these warning lights?

✓ Accepted solution

ClearTheCode Admin

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

0

ClearTheCode admin answer:

Reduced regenerative braking coupled with illuminated ABS and Traction Control lights is a critical issue that points to a problem within your vehicle's braking and stability control systems. The car's computer relies on accurate wheel speed data for both regenerative braking and safety systems.

Causes:

  1. Faulty Wheel Speed Sensor: A damaged, dirty, or disconnected wheel speed sensor (also known as an ABS sensor) at one or more wheels is a very common culprit. If the car can't accurately read wheel speed, it will disable systems that rely on that data.
  2. Damaged ABS Reluctor Ring: This magnetic ring, which the sensor reads, can become damaged, corroded, or accumulate debris, leading to incorrect readings.
  3. Wiring Harness Issue: A break, short, or corrosion in the wiring leading to a wheel speed sensor can interrupt the signal.
  4. ABS Module Failure: While less common, a fault within the ABS control module itself can cause these symptoms.

When to See a Shop: This is a critical safety issue. Reduced braking capability (even if friction brakes still work) and disabled ABS/Traction Control mean compromised vehicle safety, especially in emergency braking or slippery conditions. You should have this diagnosed and repaired by a qualified Tesla service center or an independent shop specializing in Teslas as soon as possible. Do not delay, especially if driving in adverse weather conditions.

Diagnostic Steps:

  1. Check for OBD Codes: The first and most important step is to use an OBD-II scanner (or have a shop do it) to retrieve diagnostic trouble codes. Look for codes related to wheel speed sensors or the ABS module. Common codes include:
    • C0031-C0035: Left Front Wheel Speed Sensor circuit issues.
    • C0040-C0045: Right Front Wheel Speed Sensor circuit issues.
    • C0050-C0055: Left Rear Wheel Speed Sensor circuit issues.
    • C0060-C0065: Right Rear Wheel Speed Sensor circuit issues.
    • C0020: ABS pump motor control circuit.
    • Other codes related to the ABS/Traction Control module.
  2. Visual Inspection: Once codes are retrieved, inspect the specific wheel speed sensor(s) indicated by the codes. Look for visible damage to the sensor, its wiring, or the connector. Also, check the reluctor ring (often visible behind the brake rotor) for damage or debris.
  3. Test Sensor Output: A technician can use a multimeter or oscilloscope to test the output of each wheel speed sensor to confirm if it's sending a proper signal to the ABS module.
Menu

Help & account