Powertrain, generic (extended)

P2B42 A Camshaft Position Actuator Position Sensor B Circuit High Bank 1

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

Here sensor B of the bank 1 intake actuator reports a value stuck above its upper limit. Typical reasons are an open sensor ground, a signal line touching 5 V or battery voltage, or a defective sensor. No manufacturer explains P2B42 publicly; the supplier list from NTN-SNR only names it as the inlet-side sensor B with a signal that is too high. GM measures the related sliding-cam circuits of its L3B (P2C08) for contact with supply voltage while the output is switched off, again at 0.5 Ω and 4 of 5 samples, and lights the MIL on the first trip – a comparison, not a statement about this code. On Mercedes CAMTRONIC engines the sensor sits in the actuator, so a failed sensor means replacing the actuator. Low is P2B41.

Likely causes

Sensor ground open or connector corroded

Signal wire shorted to 5 V or battery voltage

Sensor (actuator) faulty

Symptoms

Check engine light on
Intake lift change locked out
Usually no noticeable change in driving, sometimes reduced power

Repair estimate

DifficultyMediumDIY possible

Parts and labour€60–600

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.