P01B3

What it means

Intermittent signal from alternative fuel tank A level sensor. 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

• Connector loose or corroded

  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 P01B3 diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?