P2B44 code meaning
A Camshaft Position Actuator Position Sensor B Range/Performance Bank 2
Powertrain system Generic code P2Bxx codes Check engine light
What P2B44 means
P2B44 is the one code of this group with a public manufacturer use. Mercedes-Benz bulletin LI05.20-P-080192 (January 2026) lists P2B4400 on M176/M177 V8 engines – AMG 63 models, S 580, G 550, GLS 580 – and reads it as an implausible sensor signal from CAMTRONIC solenoid 2 on the intake side of bank 2. The bulletin blames software and hardware: update the engine control unit, fit the newest actuator part numbers and inspect the harness near the windshield for heat damage. Related codes in the same bulletin show the system then going into limp-home mode (P164B). In short, the signal is electrically present but disagrees with the pin movement that was commanded. Bank 1 counterpart: P2B40.
P2B44 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P2B44
- Check engine light on
- CAMTRONIC limp-home mode, cylinder deactivation off
- Higher fuel consumption at part load
Common causes of P2B44
- Most likelyEngine control software needs the CAMTRONIC update (Mercedes)
- Most likelyActuator of an older part number (Mercedes replaces it)
- PossibleHarness heat-damaged near the windshield
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
A camshaft position actuator pos sensor b b2Wiring harnessECM
What each part of P2B44 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. |
| 44 | The exact fault in that area. |
What to do next
- Note P2B44 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 P2B44
What does P2B44 mean?
P2B44 means "A Camshaft Position Actuator Position Sensor B Range/Performance Bank 2". P2B44 is the one code of this group with a public manufacturer use. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B44?
Drive gently and only to a workshop. With P2B44 the car can go into limp mode (reduced power) to protect itself.
Will P2B44 fail an emissions test?
Yes, it can. P2B44 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 P2B44 to fix?
Difficulty: workshop only. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P2B44 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.