OBD-II code · Powertrain (generic, extended)

P236D Cylinder 12 Pressure Variation Low

Cylinder-to-cylinder pressure variation on cylinder 12 is below the calibrated minimum — pressure stays unusually constant cycle-to-cycle, often a sign that the closed-loop combustion controller has lost authority or the sensor signal is filtered.

Is it safe to drive with P236D?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyWeak combustion - low cycle-to-cycle variation

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1.5–6 h
Emissions test
Likely to fail
Parts involved
Cylinder 12 Combustion, Cylinder Pressure Sensor 12

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