P2B39 code meaning
B Camshaft Profile Actuator B Control Circuit/Open Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B39 means
Camshaft B is the exhaust camshaft, and actuator B is the second shifting solenoid on it. On GM's 2.7-litre L3B the exhaust side has only two such actuators, so this is the last of them; GM's tables call it exhaust camshaft profile actuator 2. P2B39 flags an open control circuit: with the output commanded on, the ECM reads an impedance of at least 200 kΩ to ground. It needs 4 failures in 5 samples, a supply above 11 V and key in crank or run, and it turns the MIL on in the first trip. A loose connector on the camshaft carrier, a broken wire or an open coil are the usual causes. The exhaust sleeve then stays put, so the engine cannot change profile on that side. The intake counterpart is P2B33.
P2B39 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 P2B39
- MIL on in the first drive
- Exhaust lift profile no longer switches, cylinder deactivation unavailable
Common causes of P2B39
- Most likelyExhaust actuator connector loose or corroded on the camshaft carrier
- PossibleBroken wire in the engine harness
- PossibleOpen solenoid coil in exhaust actuator B
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 P2B39 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. |
| 39 | The exact fault in that area. |
What to do next
- Note P2B39 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 P2B39
What does P2B39 mean?
P2B39 means "B Camshaft Profile Actuator B Control Circuit/Open Bank 1". Camshaft B is the exhaust camshaft, and actuator B is the second shifting solenoid on it. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B39?
Drive gently and only to a workshop. With P2B39 the car can go into limp mode (reduced power) to protect itself.
Will P2B39 fail an emissions test?
Yes, it can. P2B39 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 P2B39 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2B39 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.