P2B3B code meaning
B Camshaft Profile Actuator B Control Circuit High Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B3B means
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.
P2B3B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B3B
- Check engine light comes on during the drive
- Exhaust lift stays in one profile, cylinder deactivation blocked
Common causes of P2B3B
- Most likelyControl wire chafed against a live wire in the engine harness
- PossibleInternal short in exhaust actuator B
- Less likelyEngine module output stage faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
B camshaft profile actuator b b1Wiring harnessECM
What each part of P2B3B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 3B | The exact fault in that area. |
What to do next
- Note P2B3B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2B3B
What does P2B3B mean?
P2B3B means "B Camshaft Profile Actuator B Control Circuit High Bank 1". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B3B?
Drive gently and only to a workshop. With P2B3B the car can go into limp mode (reduced power) to protect itself.
Will P2B3B fail an emissions test?
Yes, it can. P2B3B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B3B to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P2B3B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.