C0504

What it means

Intermittent or erratic signal from left-front wheel speed sensor A. Wheel-speed signals feed ABS, ESC, traction control, transmission and odometer — a single dropped signal disables all of these safety functions until repaired.

Is it safe to drive?

This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.

Most likely causes

• Connector loose or chafed wiring

  high

  One of the most commonly reported causes for this code — check this first.

• Connector with intermittent contact under vibration

  low

  Less common, but worth ruling out after the more likely causes.

• Harness routed against vibrating component

  low

  Less common, but worth ruling out after the more likely causes.

Related help

• Full C0504 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?