P04CA

What it means

Same as P04C8 with the signal voltage shorted to ground or constantly low. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

Is it safe to drive?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

• Signal shorted to ground

  high

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

• Connector pins corroded - high contact resistance

  low

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

• Harness chafing through insulation

  low

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

Related help

• Full P04CA diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?