Powertrain, generic (extended)

P2E6B System Too Rich During Cylinder Deactivation Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2E6B closes the set: bank 2 runs rich while cylinders are switched off. GM's 19OBDG07 tables (4.2-litre twin-turbo V8, LTA) fail the test when bank 2's deactivation-mode trim factor falls below 0.77 and has settled; Type B, two trips, same enable conditions as the other three codes. Typical systems keep the valves of the idle cylinders shut and stop fuelling them, so the shut cylinders act as air springs; if a valve or injector of a cylinder that should be off keeps working, measured air and real air per firing cylinder no longer match. Compared with P2E69 the fault sits on the other bank; a rich result on both banks suggests a common source such as purge vapour or fuel-diluted oil. GM calls the system Active Fuel Management.

Likely causes

Leaking injector on bank 2, including one on a cylinder that should be shut off
Deactivation rocker or its oil-control solenoid not switching on one cylinder
Excess purge vapour or fuel-diluted engine oil
Bank 2 oxygen sensor reading biased lean

Symptoms

  • Check engine light after two trips
  • Higher fuel consumption on the highway
  • Possible sooty tailpipe on bank 2 side

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

P2E69P2E6AP2180P0175

References: gsi.ext.gm.com, law.cornell.edu, en.wikipedia.org, enginelabs.com.