Powertrain, generic (extended)

P2C5D Cylinder 6 Fuel Injector B Offset Learning At Max Limit

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2C5D says injector B of cylinder 6 needs the largest learned offset allowed. Because the offset depends on how quickly the driver can energise the coil, electrical causes deserve the first look: a corroded or loose connector, chafed wiring or a supply voltage that sags on that injector lengthen the real opening delay. If a circuit code for the same valve (P21D4) is present, that comes first. Mechanical causes are deposits or a sticking pintle. On six- and eight-cylinder engines with port plus direct injection this valve is often under the intake manifold, which makes access costly. No maker documents P2C5D publicly; the only bulletin for the family, Volvo's TJ 36016, stops at cylinder 4. CARB 1968.2 (e)(6.2.2) applies.

Likely causes

Varnish or deposits in injector B of cylinder 6, slow opening

Corroded or loose connector, chafed wire or voltage drop at this injector

Old adaptation values left at the limit after a repair or software change

Air leak at the intake runner of cylinder 6 (only where the learn uses exhaust oxygen)

Symptoms

Check engine light
Often nothing else noticeable
Possibly uneven idle or lean misfire on cylinder 6

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€0–1,200

Time0.5–5 h

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

Parts involved

fuel injector b cyl 6ecm

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