how to address brake code C1234 on my Tesla Model S Plaid/Refresh (2021-present)

Learn how to diagnose and fix brake code C1234 on Tesla Model S Plaid/Refresh. Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools: Tesla diagnostic tool, multimeter, brake fluid, socket set, and safety glasses.
• Ensure the vehicle is parked on a level surface with the parking brake engaged.
• Disconnect the 12V battery to avoid electrical shorts while working on the braking system.

2. Inspect Brake Fluid

• Remove the brake fluid reservoir cap.
• Check the fluid level; it should be between the minimum and maximum marks.
• If the fluid is low, top it off with the manufacturer-recommended brake fluid (DOT 3 or DOT 4, as specified).
• Clean the cap and reseal it tightly.

3. Check Wiring and Connections

• Visually inspect the wiring harness connected to the brake system components.
• Look for frayed wires, corrosion, or loose connections.
• If any damage is found, repair or replace the damaged wiring or connectors.

4. Replace Brake Components if Necessary

• If brake pads or rotors are worn, replace them as follows:
  • Loosen the lug nuts on the wheel using a socket set.
  • Lift the vehicle using a jack and secure it with jack stands.
  • Remove the wheel to access the brake assembly.
  • Remove the caliper bolts and slide the caliper off the rotor.
  • Replace worn brake pads and, if needed, the rotor.
  • Reassemble the brake system and torque the caliper bolts to the specified value (consult service manual).

5. Reset the Brake System

• Reconnect the vehicle's 12V battery.
• Use the Tesla diagnostic tool to clear the C1234 code and reset the brake system.
• Conduct a brake system self-test through the diagnostic tool.