P2B50A Camshaft Profile Actuator B Control Performance/Stuck Off Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Bank 2 of a V-engine has its own intake camshaft (A), and P2B50 reports that the second profile actuator on it does not do its job or stays in the off position. Mercedes-Benz documents the code for the M176 and M177 V8 with CAMTRONIC (for example AMG C63, GLC63 and S 580 models): in topic LI05.20-P-080192 of January 2026, solenoid 2 for the intake side of bank 2 is described as faulty or jammed off, with fault type 07 for a mechanical and 09 for a component fault. Mercedes recommends an engine ECU software update, newer actuator part numbers and an inspection of the harness near the bulkhead, where heat can damage it. The intake lift then cannot switch on that bank. Bank 1 counterpart: P2B4F; stuck on: P2B54.
- What you may notice
- Check engine light on
- CAMTRONIC lift switching inactive on bank 2, possibly limp-home mode of the system
- Slightly uneven running or higher fuel use at part load
- Likely causes
- LikelyCAMTRONIC actuator of an older part number, superseded by Mercedes
- PossibleEngine control software that needs the available update
- PossibleHarness heat-damaged above the bulkhead near the windscreen
- RareActuator pin mechanically jammed in the retracted position
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.