Powertrain, generic (extended)

P2B44 A Camshaft Position Actuator Position Sensor B Range/Performance Bank 2

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modePossible

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.

Likely causes

Engine control software needs the CAMTRONIC update (Mercedes)

Actuator of an older part number (Mercedes replaces it)

Harness heat-damaged near the windshield

Symptoms

Check engine light on
CAMTRONIC limp-home mode, cylinder deactivation off
Higher fuel consumption at part load

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€150–1,000

Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

a camshaft position actuator pos sensor b b2wiring harnessecm

References: static.nhtsa.gov, law.cornell.edu, ntn-snr.com.