P2B3AB Camshaft Profile Actuator B Control Circuit Low 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
- P2B3A points to a short to ground in the control line of exhaust-side actuator B on bank 1, i.e. the second pin solenoid that slides the lobe sleeve along camshaft B. GM documents it for the L3B four-cylinder in its 2019 and 2025 OBD tables: driver on, a resistance to ground not above 0.5 Ω, 4 of 5 samples, supply over 11 V, Type A with immediate MIL. Unlike its neighbours, P2B3A is missing from the code list of bulletin PIT5677, which prints P2B39 twice instead, yet the harness chafing over the camshaft carrier described there produces exactly this kind of ground fault. With the exhaust sleeve stuck, the engine loses part of its lift switching. Open and short to power are P2B39 and P2B3B.
- What you may notice
- Check engine light on immediately
- Exhaust profile and cylinder deactivation no longer switch
- With harness damage often further codes and rough running
- Likely causes
- LikelyEngine harness rubbed through where it crosses the camshaft carrier
- PossibleShorted turns in exhaust actuator B
- RareOil wicking into the actuator connector
- 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
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.