P03C0 Cylinder 5 Pressure Sensor Circuit High

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. P03C0 means the sensor signal stays above its upper limit – typically an unplugged connector, an open signal or ground wire, or a short to positive. The only manufacturer we found using this code family, GM's European 2.0 CDTI four-cylinder diesel (Saab 9-5, 2010), uses it for cylinders 1 to 4: signal above the threshold for more than 2 s with the engine running, check engine light after two trips, displayed pressure 10,000 kPa. 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. Without the signal, combustion control for this cylinder is switched off.

Likely causes

Symptoms

• Check engine light on (often after two trips)
• Usually barely noticeable – combustion control for the cylinder is switched off
• Possibly rougher running, more noise or slightly higher consumption

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, saabwisonline.com, borgwarner.com.