Diagnostic article Generic OBD-II
P03A2: Cylinder 2 pressure-sensor high input and ground integrity
The documented Mazda P03A2 procedure covers cylinder 2 pressure-sensor high input and ground integrity.
Read before applying this article
Documented application
Mazda3 workshop manual 01/2019 onward, d9n1-1a-22d_ver10; PCM (SKYACTIV-X). Verify exact vehicle specification; this is a Mazda application example.
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.
P03A2 identifies cylinder 2 pressure-sensor circuit high input. In Mazda's SKYACTIV-X monitor, the voltage must exceed 4.84 V for five seconds.
A high reading can follow a missing ground
The factory cause list includes both a signal short to power and an open sensor ground. These need different repairs despite producing the same high-input report. Sensor or PCM connector problems, an internal sensor fault and a PCM fault are additional possibilities.
Before concentrating on number 2 alone, Mazda checks for P0398, P03AC or P03B6 in the other cylinders. A companion high-input code changes the diagnostic route toward the PCM connection. The pattern across the engine is therefore part of the evidence, not incidental scan information.
Keep circuit testing and function testing separate
The isolated branch assesses the number 2 connector and sensor resistance. Subsequent checks address signal exposure to power, ground continuity and sensor function. Passing a resistance check does not establish that the sensor provides valid pressure feedback in operation.
The documented response inhibits EGR and SPCCI, stops combustion feedback and retards ignition. P03A2 is not proof that cylinder 2 pressure is physically excessive. After repair, the specified self-test and pending-code inspection confirm whether the electrical failure has returned; any separate combustion or compression concern still requires its own evidence.
Documented application
Mazda3 workshop manual 01/2019 onward, d9n1-1a-22d_ver10; PCM (SKYACTIV-X). Verify exact vehicle specification; this is a Mazda application example. Mazda factory diagnostic page, mirrored by CHARM.
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
Cylinder 2 Pressure Sensor Circuit High
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