Powertrain, generic · Fuel and air metering (injector circuit)

P02D6 Cylinder 6 Fuel Injector A Offset Learning At Min Limit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The engine module learns a small-quantity correction for each injector: on overrun it gives one injector a tiny test injection (GM about 1.5 mm³), measures the resulting crankshaft acceleration and corrects the injector's activation time per rail pressure step. P02D6 means the learned correction for cylinder 6 has reached its lower limit at at least one pressure step: the injector needs much less activation time than nominal – it delivers too much at small quantities or opens early. GM diesels set it at limits of roughly ±66–182 µs after two trips. It is documented on GM's 6.6 litre L5P diesel and on Land Rover's 5.0 V8 petrol, where a software update is the first step. It differs from P01D6 (over advanced), which some systems derive from the same learning.

Likely causes

Injector of cylinder 6 leaking or over-delivering at small quantities
Engine software (update available for some models)
Injector correction code not or wrongly programmed after replacement
Disturbed crankshaft signal (worn drive belt, tone wheel, dual-mass flywheel)

Symptoms

  • Check engine light on
  • Often nothing noticeable; possibly rough idle or knocking
  • Possibly smoke or higher consumption

Repair estimate

DifficultyHardWorkshop job
Parts and labour€0–1,200
Time0.5–4 h

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

Parts involved

fuel injector cylinder 6crankshaft position sensorengine control module

Related codes

P02D7P01D6P020FP0278P0206P026C

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.