P3623critical severityPowertrain
Cylinder Deactivation Lifter Stuck Activated
on 2014 Cadillac ATS 2.0L Turbo I4 · RWD
What this code means
A cylinder deactivation lifter is mechanically stuck in the deactivated (collapsed) position. The affected cylinder is not firing.
Symptoms
- Check Engine Light
- Engine misfire
- Rough idle and vibration
- Reduced power
- Exhaust smell of unburned fuel
- Catalytic converter damage risk
Common causes
- Collapsed lifter mechanism
- Oil sludge jamming lifter
- Lifter roller bearing failure
- Oil pressure loss to lifter
- Excessive wear on lifter body
Diagnostic steps
- Identify which cylinder is deactivated permanently
- Check oil pressure at affected lifter
- Perform compression test on that cylinder
- Check for oil sludge
- Inspect lifter via valve cover removal if accessible
Repair notes
Replace collapsed deactivation lifter. This requires camshaft and lifter removal. Inspect cam lobe for damage. Full engine oil flush recommended.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1