Brake Light Switch

Replace the brake light switch on a 2012 Tesla Roadster. The Roadster is built on the Lotus Elise platform, so the switch is a Lotus-sourced component mounted on the brake pedal bracket under the dash.

Warnings

Tools required

Parts

• Brake light switch (Lotus Elise/Roadster spec) × 1 — Manufacturer-specified brake light switch — verify against VIN with Tesla Roadster parts catalog

Preparation

1. Park on level ground, place in P (or in gear if manual transmission variant), engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage auxiliary battery. On the 2012 Roadster the 12V battery is located in the front trunk area — refer to the Roadster Owner's Manual for exact access.
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Position the driver's seat fully rearward and tilt the steering wheel up (if adjustable) for footwell access. The Roadster has an extremely cramped footwell — be patient.
7. Have a flashlight ready; the brake pedal bracket is poorly lit even with the door open.

Procedure

1. 1

   Locate the brake light switch
   Lying on your back in the driver footwell, look up at the top of the brake pedal assembly. The brake light switch is threaded into a bracket above the brake pedal arm and contacts a tab on the pedal when the pedal is at rest. It will have a small 2-wire electrical connector attached.
2. 2

   Disconnect the electrical connector
   Depress the locking tab on the switch's electrical connector and pull it straight off. The connectors on this vehicle are over a decade old and become brittle — apply gentle, even pressure. Inspect the connector terminals for corrosion or heat damage and note for later.
   ⚠If the connector locking tab breaks, the connector may need to be replaced or repaired — do not force it.
3. 3

   Remove the old switch
   The brake light switch on the Roadster is typically either a quarter-turn bayonet style or a threaded type with a locknut, consistent with the Lotus Elise donor platform. Identify which type is fitted: for bayonet style, depress and rotate counterclockwise approximately a quarter turn to release; for threaded style, loosen the locknut and unscrew the switch from the bracket. Note the depth/position of the original switch before removal — this sets the activation point.
   ⚠Do not pry against the pedal box bracket with metal tools — the bracket is part of the chassis structure.
4. 4

   Compare old and new switches
   Place the old and new switches side by side. Confirm body length, plunger length, thread pitch (if threaded), and connector style all match. If anything differs, STOP and verify part number before installing — an incorrect switch can cause permanent brake-light-on or brake-lights-never-on conditions.
5. 5

   Install the new switch
   Install the new switch into the bracket using the same method as removal. For threaded types, thread it in until the plunger just contacts the pedal arm at rest, then back off per the manufacturer's adjustment specification and tighten the locknut. For bayonet types, insert and rotate clockwise to lock. The pedal at rest should fully depress the plunger so the switch is OPEN (lights off); releasing the pedal should not allow the lights to come on, and pressing the pedal should turn lights on within the first few millimeters of travel.
   ℹ️There is no published Tesla torque spec for this switch. Hand-tight plus locknut snug is correct — do not use a torque wrench on a plastic switch body.
6. 6

   Reconnect the electrical connector
   Push the connector straight onto the new switch until the locking tab clicks. Give a gentle tug to confirm it is fully seated.

Reassembly

1. Reconnect the 12V auxiliary battery (negative terminal last).
2. Allow the vehicle's low-voltage systems to wake and self-check before testing — on the Roadster this can take 10-30 seconds after 12V reconnection.
3. Return the driver's seat and steering wheel to their original positions.

Verification

• With the key in the ON position (or vehicle 'ready'), have an assistant observe the rear of the car. Press the brake pedal — both rear brake lights and the CHMSL (center high-mount stop lamp) should illuminate immediately.
• Release the pedal — all brake lights should extinguish completely. Watch for a half-second to confirm no lingering glow.
• Cycle the pedal 5-10 times and confirm consistent on/off behavior with no flicker.
• Confirm that the vehicle will shift out of P/neutral only with the brake pedal pressed (brake-shift interlock function on applicable variants).
• Confirm cruise control (if equipped) cancels when the brake pedal is tapped.
• Check the instrument cluster for any new warning lights. Clear any stored faults if you have access to Roadster diagnostic equipment.
• Note: While under the dash, this is a good opportunity to confirm brake fluid was changed within the last 2 years — Tesla's published recommendation is brake fluid replacement every 2 years regardless of mileage.

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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