Powertrain, generic (extended)

P2E69 System Too Rich During Cylinder Deactivation Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2E69 is the rich mirror of P2E68: with cylinders deactivated, bank 1 has to pull fuel out beyond the permitted range. In GM's 19OBDG07 tables for the 4.2-litre twin-turbo V8 the separate long-term trim factor learned for deactivation mode must drop below 0.77 and stay steady; it shares the enable logic of P2E68 and is Type B, MIL on the second trip. A Ford patent on variable displacement V8s shows how such a rich shift arises: if one cylinder fails to deactivate, air blows through it, the airflow meter reports more air, fuel rises accordingly, and the bank that is working normally runs rich. A leaking injector on a firing cylinder or a fuel-diluted crankcase can do the same. The running-mode rich codes are separate.

Likely causes

A cylinder that should be off still breathing, so measured airflow and fuel delivery are too high
Leaking or dribbling direct injector on bank 1
Fuel vapour from diluted oil or a stuck-open purge valve
Bank 1 oxygen sensor reading biased lean

Symptoms

  • Check engine light after two trips
  • Higher fuel use, possible fuel smell
  • Rough running in deactivation mode

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,000
Time1–8 h

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

Parts involved

fuel injectorsdeactivation solenoidsintake system

Related codes

P2E6BP2E68P2178P0172P3400

References: gsi.ext.gm.com, law.cornell.edu, image-ppubs.uspto.gov, enginelabs.com.