OBD-II code · Powertrain (generic, extended)

P2C51 Fuel Level Sensor A/B Correlation

The signals of fuel level sensors A and B do not correlate within the calibrated tolerance. Common in saddle tanks where two sensors monitor each tank half.

Is it safe to drive with P2C51?

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

Common causes

  • Most likelyOne float stuck on guide rod
  • PossibleSaddle tank transfer pump failed

Repair at a glance

Difficulty
Medium
DIY friendly
Best left to a mechanic
Typical labour
1–5 h
Emissions test
Usually unaffected
Parts involved
Fuel Level Sensor A, Fuel Level Sensor B, Ecm

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