Obdaryn

P2B33A Camshaft Profile Actuator B Control Circuit/Open Bank 1

  • Generic OBD-II code · Powertrain
  • Turns on the check-engine light
  • Matters for the ITP
  • Can trigger limp mode
How the car detects it
P2B33 concerns the second profile actuator on the intake camshaft (camshaft A) of bank 1. Such actuators are solenoids that extend a pin into a groove on a sliding cam sleeve and so move lobes of a different lift under the valves. GM uses the code on the 2.7-litre turbo four L3B (Silverado and Sierra 1500 from 2019), whose sliding cam system has four intake and two exhaust actuators; GM calls this one actuator 2. The ECM energises the output and flags an open circuit when it sees 200 kΩ or more between signal and ground in 4 of 5 samples, with supply above 11 V; MIL on the first trip (Type A). With the sleeve unable to move, lift switching and cylinder deactivation stay locked out. Low and High are P2B34 and P2B35.
What you may notice
  • MIL on after the first drive with the fault
  • No change of intake lift profile, less pull or higher fuel use depending on the stuck profile
  • Cylinder deactivation no longer engages
Likely causes
  • LikelyConnector at the actuator on the camshaft carrier loose, corroded or not latched after valve cover work
  • PossibleSolenoid winding of actuator B open
  • PossibleControl wire broken in the engine harness
  • RareOutput stage in the engine control module faulty
Inspection (ITP)
Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
Repair
Medium · Usually a job for a workshop.Typical cost: €80 – €600

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.