P2B34 code meaning
A Camshaft Profile Actuator B Control Circuit Low Bank 1
Powertrain system Generic code P2Bxx codes Check engine light
What P2B34 means
On bank 1 the intake camshaft (A) carries a second shifting solenoid, actuator B, which GM's L3B 2.7-litre four labels actuator 2. P2B34 reports a short to ground on its control line: while the driver is switched on, the ECM measures 0.5 Ω or less from signal to ground and stores the fault after 4 failed out of 5 samples at more than 11 V, lighting the MIL at once (Type A). GM bulletin PIT5677, later 21-NA-149, names P2B34 among the codes a damaged engine harness can produce when it rubs through on the camshaft carrier or near the left shock tower; fuses may blow as well. The cam sleeve then cannot be shifted, so the engine runs without lift change or cylinder deactivation. The open circuit has its own code, P2B33.
P2B34 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 P2B34
- MIL on, often together with other codes from the same harness section
- Lift switching and cylinder deactivation unavailable
- With a chafed harness also rough running, reduced power or blown fuses
Common causes of P2B34
- Most likelyEngine harness chafed through on the camshaft carrier or near the left shock tower (GM PIT5677)
- PossibleShorted turns or short to housing in actuator B
- Less likelyOil or moisture in the actuator connector creating a path to ground
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 P2B34 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. |
| 34 | The exact fault in that area. |
What to do next
- Note P2B34 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 P2B34
What does P2B34 mean?
P2B34 means "A Camshaft Profile Actuator B Control Circuit Low Bank 1". On bank 1 the intake camshaft (A) carries a second shifting solenoid, actuator B, which GM's L3B 2.7-litre four labels actuator 2. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B34?
Drive gently and only to a workshop. With P2B34 the car can go into limp mode (reduced power) to protect itself.
Will P2B34 fail an emissions test?
Yes, it can. P2B34 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 P2B34 to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P2B34 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.