Powertrain, generic (extended)

P2B3F A Camshaft Position Actuator Position Sensor B Circuit Bank 1

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P2B3F is the general circuit code for position sensor B of the intake camshaft actuator (camshaft A) on bank 1, the side with cylinder 1; the NTN-SNR sensor guide also places it on the inlet side. Mercedes-Benz uses this code family on its M176/M177 V8 engines, where each CAMTRONIC lift actuator reports its own sensor signal and sensor B belongs to solenoid 2. No manufacturer documents P2B3F itself publicly. For comparison, GM's 2.7-litre L3B judges the feedback circuits of its sliding-cam actuators (P2C05 ff) as open once it sees 200 kΩ or more between signal and ground in 4 of 5 samples, Type A. Expect a broken wire, a loose plug or a failed sensor; the engine control then locks out the lift change. Low and High faults have their own codes, P2B41 and P2B42.

Likely causes

Connector at the actuator loose, corroded or wire broken

Position sensor in the actuator failed (actuator replacement)

Engine harness damaged by heat or chafing

Engine control module fault

Symptoms

Check engine light on
Lift switching or cylinder deactivation unavailable
Slightly higher consumption, sometimes less power

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€80–650

Time0.5–3 h

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

Parts involved

a camshaft position actuator pos sensor b b1wiring harnessecm

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