What does code P03C4 mean?

Q: What does code P03C4 mean?

Cylinder 5 Pressure Variation Low. P03C4 means the engine computer has detected that cylinder 5 is producing less pressure variation during the combustion cycle than the other cylinders, based on crankshaft speed fluctuations. The powertrain control module (PCM) uses the crankshaft position sensor signal to calculate each cylinder's contribution to engine speed and flags this code when cylinder 5 consistently underperforms.

DTC codes / P03xx · Ignition system and misfire / P03C4

P03C4Cylinder 5 Pressure Variation Low

P03C4 means the engine computer has detected that cylinder 5 is producing less pressure variation during the combustion cycle than the other cylinders, based on crankshaft speed fluctuations. The powertrain control module (PCM) uses the crankshaft position sensor signal to calculate each cylinder's contribution to engine speed and flags this code when cylinder 5 consistently underperforms.

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.