Powertrain, shared range

P34BC B Camshaft Position Actuator Position Sensor A Circuit Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P34BC means the module cannot make sense of the wiring of sensor A, which reports where actuator B on bank 1 stands. Read against the NTN-SNR list, actuator B is the exhaust-side one. Where such actuators are electric, sensor A reports the motor or phaser angle; Mitsubishi shows the intake equivalent P34AC, set after a voltage outside the window for one second or more. Mercedes-Benz files the feedback of its CAMTRONIC exhaust solenoid on its M176/M177 eight-cylinder units in this very group, yet its bulletin lists only the range and low codes P34BD and P34BE, not the general circuit code. No public source covers P34BC itself, so diagnosis stays generic: unplugged connector, broken wires, missing sensor supply, then the actuator. Bank 2 counterpart: P34C0.

Likely causes

Connector at the exhaust actuator unplugged or corroded, wire broken
Sensor supply or ground missing
Sensor integrated in the actuator failed (actuator replacement)

Symptoms

  • Malfunction indicator lamp lit
  • Exhaust-side adjustment on bank 1 switched off
  • Possibly slightly higher fuel consumption

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–4 h

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

Parts involved

cam actuator b pos sensor b1sensor wiring

Related codes

P34BDP34BEP34BFP34C0P34ACP2B47

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