P2B3A: B Camshaft Profile Actuator B Control Circuit Low Bank 1

P2B3A points to a short to ground in the control line of exhaust-side actuator B on bank 1, i.e. the second pin solenoid that slides the lobe sleeve along camshaft B. GM documents it for the L3B four-cylinder in its 2019 and 2025 OBD tables: driver on, a resistance to ground not above 0.5 Ω, 4 of 5 samples, supply over 11 V, Type A with immediate MIL. Unlike its neighbours, P2B3A is missing from the code list of bulletin PIT5677, which prints P2B39 twice instead, yet the harness chafing over the camshaft carrier described there produces exactly this kind of ground fault. With the exhaust sleeve stuck, the engine loses part of its lift switching. Open and short to power are P2B39 and P2B3B.

Medium severity. Can I keep driving?Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Check engine light on immediately
Exhaust profile and cylinder deactivation no longer switch
With harness damage often further codes and rough running

Most likely causes

Engine harness rubbed through where it crosses the camshaft carrier
Shorted turns in exhaust actuator B
Oil wicking into the actuator connector

What to check, in order

Start with the simplest. You can tick off each step.

Check the oil level and condition before anything else
With the connector unplugged, check whether the signal wire is making contact with ground.
Check the solenoid valve's connector
Compare commanded and actual angles in live data
Test the solenoid valve and its filter, if it has one
Check the engine timing if there is chain noise

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P2B3A means

P: Powertrain: engine and transmission
2: Generic code: same on every make
B: Subsystem depends on the code range
3A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2B3A?

Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

What causes code P2B3A?

The most common causes are: engine harness rubbed through where it crosses the camshaft carrier; shorted turns in exhaust actuator B; oil wicking into the actuator connector.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.