Powertrain, generic (extended)

P2C52 Cylinder 1 Fuel Injector B Offset Learning At Min Limit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Engines with two injectors per cylinder call the second one injector B; with port plus direct injection that is usually one of the two sets, but which one is the maker's choice. For every B injector the engine control learns an offset, a correction for the dead time between the electrical command and the start of real fuel flow. P2C52 says this correction for cylinder 1 has been pushed to its lowest permitted value: the injector already passes more fuel than its model expects, and the pulse cannot be shortened any further. CARB 13 CCR 1968.2 (e)(6.2.2) counts an adaptation that has used up its authority as a malfunction. No manufacturer publishes this exact code; Volvo's Technical Journal 36016 names only the Max partner P2C53.

Likely causes

Injector B of cylinder 1 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 1
  • 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 1ecm

Related codes

P2C53P02CCP02CDP21CFP2BF1P0301

References: law.cornell.edu, patents.google.com, static.nhtsa.gov.