P03A7Cylinder 2 Pressure Variation High
- 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. GM's European 2.0 CDTI diesel (Saab 9-5, 2010) uses P03A7 as 'pressure variation too high' and sets it when the signal is outside its range for more than 0.2 s with the engine running; its fault table counts it among the signal performance faults together with the erratic code. What exactly is measured, Saab does not explain; presumably it is the swing of the pressure signal within an engine cycle – too large a swing points to a noisy or overshooting signal or implausible pressure peaks, for example from faulty sensor electronics, interference on the signal wire or, less often, a combustion anomaly such as a dripping injector. Usually there are no noticeable symptoms.
- What you may notice
- Check engine light on
- Usually no noticeable symptoms
- Possibly rough running or combustion noise because control is off
- Likely causes
- LikelySensor in the glow plug faulty (signal noise)
- PossibleLoose contact or interference on the signal wire
- RareCombustion anomaly (dripping injector, harsh combustion)
- 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: €100 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.