Diagnostic article Generic OBD-II
P2B3A: Exhaust profile-actuator circuit low is an on-state electrical finding
Learn how P2B3A’s driver feedback differs from a low mechanical position or a failed profile transition.
Read before applying this article
Documented application
2025 GM 25OBDG03B documented monitor only. Vehicle, engine and calibration applicability must be confirmed from the matching service information; no model fitment is inferred.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P2B3A concerns the exhaust profile-actuator output being electrically low while commanded on. The GM monitor describes a short-to-ground classification for exhaust actuator 2. The low label does not describe exhaust cam angle, valve lift or where the profile pin physically rests.
Read the electrical classification in context
Controller-specific voltage limits are calibrated to an impedance below 0.5 Ω toward controller ground. This information explains the classification but does not define a universal connector test. The actual output command must be known before a low signal can be interpreted.
The related open-circuit row also examines the energized output, but represents a different electrical path condition. Recording the exact subtype avoids reducing every nonresponsive actuator to the same mechanical explanation.
Establish an eligible repeated result
The source requires system voltage above 11 V, diagnostic enablement, a commanded-on output and ignition in crank or run. Four failed samples out of five are needed for the stated result. The one-trip reporting class should not be confused with the number of individual samples.
Preserve the channel identity, command and driver evidence together. The generic actuator-B designation must be mapped through vehicle-specific information before locating the circuit described as actuator 2 in this file. P2B3A does not establish where a ground path lies or prove that the actuator itself is the failed component.
Source and applicability
2025 GM 25OBDG03B documented monitor only. Vehicle, engine and calibration applicability must be confirmed from the matching service information; no model fitment is inferred. These criteria explain controller logic, not a complete repair procedure. 25OBDG03B, PDF page 873. 25OBDG03B, PDF page 874. 25OBDG03B, PDF page 875.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
B Camshaft Profile Actuator B Control Circuit Low Bank 1
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT