P03A0Cylinder 2 Pressure Sensor Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Some diesels have a combustion pressure sensor in the glow plug; the engine module uses it to control injection for each cylinder. This code concerns cylinder 2. P03A0 means the sensor signal is electrically fine but does not fit the expected value. No manufacturer document available to us describes the code; a GM patent shows how such a check works: in overrun the measured peak pressure is compared with a compression pressure calculated from manifold pressure and compression ratio, and the pressure values are also compared with limits and with crankshaft speed fluctuation. GM's European diesel in the Saab 9-5 uses the peak pressure in overrun anyway to find top dead centre. Typical causes are sensor drift from combustion deposits or a glow plug that leaks or is wrongly torqued. CARB requires a two-sided plausibility check of input sensors where feasible.
- What you may notice
- Check engine light on
- Combustion control for the cylinder off – slightly rough running, more noise
- Possibly more smoke or consumption
- Likely causes
- LikelySensor in the glow plug drifting (deposits, ageing)
- PossibleGlow plug leaking or wrongly torqued (pressure transmitted wrongly)
- PossibleContact resistance in connector or ground
- RareActual compression pressure differs (valve, rings)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €120 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.