P2B4F code meaning
A Camshaft Profile Actuator B Control Performance/Stuck Off Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B4F means
P2B4F covers the second profile actuator (B) on the intake camshaft of bank 1, a solenoid whose pin engages a groove on a sliding cam sleeve to change valve lift. Despite the title wording, GM's L3B 2.7-litre four (19OBDG03D, again in 25OBDG03B) uses it for the reverse case: a Hall element reports three pin states (extending 55, extended 45, retracted 68), and if the signal falls below 55 although no shift was commanded, the pin has fired on its own. Four wrong readings in five cylinder events with the engine running and more than 11 V set a Type A fault, MIL at once. The supplier NTN-SNR lists the code as actuator never active. A pin stuck out on the same actuator is P2B53; wiring faults sit under P2B33–P2B35.
P2B4F 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 P2B4F
- MIL on in the first drive with the fault
- Intake lift switching locked out, less pull or higher consumption
- Cylinder deactivation no longer available
Common causes of P2B4F
- Most likelyActuator B pin extends without a command (sticking solenoid, weak return spring)
- PossibleHall feedback of the actuator delivers wrong pin states
- Less likelyShift groove on the cam sleeve worn so the pin is dragged out
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
A camshaft profile actuator b b1Wiring harnessECM
What each part of P2B4F 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. |
| 4F | The exact fault in that area. |
What to do next
- Note P2B4F 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 P2B4F
What does P2B4F mean?
P2B4F means "A Camshaft Profile Actuator B Control Performance/Stuck Off Bank 1". P2B4F covers the second profile actuator (B) on the intake camshaft of bank 1, a solenoid whose pin engages a groove on a sliding cam sleeve to change valve lift. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B4F?
Drive gently and only to a workshop. With P2B4F the car can go into limp mode (reduced power) to protect itself.
Will P2B4F fail an emissions test?
Yes, it can. P2B4F 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 P2B4F to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2B4F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.