What does code P03BB mean?

Q: What does code P03BB mean?

Cylinder 4 Pressure Variation High. P03BB indicates that the powertrain control module has detected an abnormal pressure variation in cylinder 4, typically by monitoring the crankshaft speed fluctuations that occur during each combustion event. The computer compares the expected smooth rotation of the crankshaft to the actual signal and flags this code when cylinder 4's contribution deviates beyond a calibrated threshold.

DTC codes / P03xx · Ignition system and misfire / P03BB

P03BBCylinder 4 Pressure Variation High

P03BB indicates that the powertrain control module has detected an abnormal pressure variation in cylinder 4, typically by monitoring the crankshaft speed fluctuations that occur during each combustion event. The computer compares the expected smooth rotation of the crankshaft to the actual signal and flags this code when cylinder 4's contribution deviates beyond a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.