OBD-II code · Powertrain (generic)

P01B3 Alternative Fuel Tank A Level Sensor Circuit Intermittent/Erratic

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 with P01B3?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyConnector loose or corroded
  • Less likelyConnector with intermittent contact under vibration
  • Less likelyHarness routed against vibrating component

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.5–2 h
Emissions test
Usually unaffected
After the fix
A drive cycle is needed before the light stays off
Parts involved
Alt Fuel Tank Level Sensor, Sensor Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.