P2B3BB Camshaft Profile Actuator B Control Circuit High 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
- For the second exhaust-camshaft profile actuator on bank 1 (camshaft B, actuator B), P2B3B means its control circuit is shorted to a voltage source. GM's L3B strategy checks this with the driver switched off: a resistance of no more than 0.5 Ω between the line and controller power counts as a fault, and four out of five such readings at a supply above 11 V store a Type A code, MIL on at once. Bulletin 21-NA-149, which covers chafed engine harnesses on 2019–2021 Silverado and Sierra 1500 pickups including the L3B, lists P2B3B among the possible codes. The affected exhaust sleeve can no longer be shifted on command, so the valve lift on that side stays as it is. P2B35 is the same fault on the intake side.
- What you may notice
- Check engine light comes on during the drive
- Exhaust lift stays in one profile, cylinder deactivation blocked
- Likely causes
- LikelyControl wire chafed against a live wire in the engine harness
- PossibleInternal short in exhaust actuator B
- RareEngine module output stage 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
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.