P2B50 code meaning
A Camshaft Profile Actuator B Control Performance/Stuck Off Bank 2
Powertrain system Generic code P2Bxx codes Check engine light
What P2B50 means
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.
P2B50 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B50
- 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
Common causes of P2B50
- Most likelyCAMTRONIC actuator of an older part number, superseded by Mercedes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 windshield
- Less likelyActuator pin mechanically jammed in the retracted position
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
A camshaft profile actuator b b2Wiring harnessECM
What each part of P2B50 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 50 | The exact fault in that area. |
What to do next
- Note P2B50 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2B50
What does P2B50 mean?
P2B50 means "A Camshaft Profile Actuator B Control Performance/Stuck Off Bank 2". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B50?
Drive gently and only to a workshop. With P2B50 the car can go into limp mode (reduced power) to protect itself.
Will P2B50 fail an emissions test?
Yes, it can. P2B50 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B50 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2B50 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.