Powertrain, generic (extended)

P2EAD Reductant Metering Unit 2 Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Some diesels dose DEF at two points, each with its own metering unit or injector. P2EAD means the second one no longer delivers what it should. GM documents it for the 3.0 L Duramax LZ0, where its table calls it injector 2 performance with low consumption: the control unit compares the pressure drop expected while the second injector doses with what it measures and builds a correction factor; once the averaged factor passes the calibrated limit, proper delivery is no longer assured and the code sets as type A, MIL after one trip. Unit 1 has P20FE. GM bulletin 23-NA-193 lists P2EAD among codes on 2023 Silverado and Sierra 1500 caused by software and cured by an engine module update. Otherwise a crusted or partly blocked injector or a kinked line is usual.

Likely causes

Second DEF injector crusted or partly blocked by urea crystals
Kinked, frozen or blocked line to the second injector
Engine control software needing an update (GM LZ0 2023)
Weak DEF pump or pressure sensor deviation

Symptoms

  • Check engine lamp on
  • DEF warning and, if not repaired, speed limitation
  • Higher NOx emissions

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time0.5–4 h

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

Parts involved

reductant metering unit 2reductant injection valveengine control module

Related codes

P20FEP2EAEP2EAFP2053

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