P2B55 code meaning
B Camshaft Profile Actuator B Control Stuck On Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B55 means
P2B55 flags actuator B on the bank 1 exhaust camshaft as stuck on. Even GM, whose L3B four has a second exhaust actuator and uses P2B51 for it, lists no stuck-on code for that actuator in its 2019 and 2025 tables; no other maker documents P2B55 publicly either. The fault logic can be inferred from the intake twin P2B53: a pin that does not report back to its rest position after shifting. NTN-SNR lists the code as component permanently active, and CARB (e)(13) covers it as a valve control fault. A sleeve held in one exhaust profile changes scavenging and turbo response, and the engine control normally locks out further switching. Related: P2B51 (stuck off), P2B39–P2B3B (circuit).
P2B55 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B55
- Check engine light on
- Changed turbo response or reduced power
- Possible metallic noise from the camshaft area
Common causes of P2B55
- Most likelyPin of exhaust actuator B does not retract, often from heat and deposits
- PossibleSolenoid stays powered because of a wiring or driver fault
- Less likelyDamaged shift groove holds the pin
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 P2B55 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. |
| 55 | The exact fault in that area. |
What to do next
- Note P2B55 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 P2B55
What does P2B55 mean?
P2B55 means "B Camshaft Profile Actuator B Control Stuck On Bank 1". P2B55 flags actuator B on the bank 1 exhaust camshaft as stuck on. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B55?
Drive gently and only to a workshop. With P2B55 the car can go into limp mode (reduced power) to protect itself.
Will P2B55 fail an emissions test?
Yes, it can. P2B55 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 P2B55 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2B55 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.