Powertrain, shared range

P34BD B Camshaft Position Actuator Position Sensor A Range/Performance Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P34BD has a documented user. Mercedes-Benz lists P34BD09 in bulletin LI05.20-P-080192, dated 14 January 2026, for M176/M177 V8 engines with CAMTRONIC, used for example in the AMG C 63 and E 63, the G 550 and the Maybach GLS 600. Its fault text reports the feedback from exhaust-side CAMTRONIC solenoid 1 of bank 1 as faulty and classes it as a component fault. Mercedes names software and hardware as the cause: update the ME engine control unit, check the part numbers of all CAMTRONIC actuators and replace older ones (A177 982 03 03 or 17 00 by 19 00, 02 03 or 16 00 by 18 00), and look for heat-damaged wiring at the bulkhead. P005A (exhaust solenoid 1 jammed off) and the limp-home code P164B often come along. Bank 2: P34C1.

Likely causes

Engine control software outdated (Mercedes M176/M177: update)
CAMTRONIC actuator of a superseded part number
Harness heat-damaged above the bulkhead

Symptoms

  • Check engine light on
  • CAMTRONIC in limp-home mode, often with further CAMTRONIC codes

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,500
Time1–5 h

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

Parts involved

cam actuator b pos sensor b1

Related codes

P34BCP34BEP34BFP34C1P005AP2B48

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