P03C5Cylinder 5 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 5. P03C5 means the swing of the pressure signal is too large. The only manufacturer we found using this code family, GM's European 2.0 CDTI four-cylinder diesel (Saab 9-5, 2010), uses 'pressure variation too high' for cylinders 1 to 4: signal outside its range for more than 0.2 s with the engine running; what exactly is measured, Saab does not explain – presumably a noisy or overshooting signal, from faulty sensor electronics, interference or a combustion anomaly. For cylinder 5, which only engines with at least 5 cylinders have, no manufacturer document available to us uses the code; the description follows that logic and CARB. 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.