Powertrain, generic (extended)

P2C56 Cylinder 3 Fuel Injector B Offset Learning At Min Limit

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2C56 is set once injector B of cylinder 3 has its learned offset stuck at the minimum. How such a value is learned is shown in Ford patents for engines that combine both injection types: with the lift pump switched off, the port injectors fire one cylinder at a time while the others run on direct injection, and how far the low-pressure rail sags after every pulse shows how much fuel that injector really released. If cylinder 3 keeps releasing more than expected, the correction moves down until it reaches the floor. Typical sources are a leaking seat or an internal leak that adds fuel between pulses. No manufacturer documents this code publicly; it also exists on three-cylinder engines. CARB 1968.2 (e)(6.2.2) makes an exhausted adaptation a fault.

Likely causes

Injector B of cylinder 3 leaking at the seat and adding fuel after closing

Replacement injector of a different flow rating or not matched to the engine software

Learned values or engine software not up to date (Volvo pairs an update with an adaptation reset for the related Max codes)

Supply pressure on this injector set higher than the model assumes (regulator)

Symptoms

Check engine light
Often nothing else noticeable
Long hot start or rough first seconds, possibly misfire on cylinder 3
Possibly fuel smell or higher consumption

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€0–900

Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injector b cyl 3ecm

References: law.cornell.edu, patents.google.com, patents.google.com.