P03CE code meaning
Cylinder 6 Pressure Variation Low
Powertrain system Generic code P03xx codes Check engine light
What P03CE means
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 6. P03CE means the swing of the pressure signal is too small. 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 low' 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 the signal barely responds, for example because a coked glow rod no longer transmits the pressure. For cylinder 6, which only engines with at least 6 cylinders have, no manufacturer document available to us uses the code; the description follows that logic and CARB. Usually there are no noticeable symptoms.
P03CE at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor1 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P03CE
- Check engine light on
- Usually no noticeable symptoms
- Possibly rough running or combustion noise because control is off
Common causes of P03CE
- Most likelyPressure-sensing glow plug faulty or coked (glow rod stuck)
- PossibleContact resistance in connector or ground
- Less likelyActual compression loss or misfire in the cylinder
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder pressure sensor glow plugSensor wiringEngine control module
What each part of P03CE means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3 | Area: ignition system or misfire. |
| CE | The exact fault in that area. |
What to do next
- Note P03CE and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P03CE
What does P03CE mean?
P03CE means "Cylinder 6 Pressure Variation Low". Some diesels have a combustion pressure sensor in the glow plug; the engine module uses it to control injection for each cylinder. It is a generic code, so it means the same on every make.
Is it safe to drive with P03CE?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P03CE fail an emissions test?
Yes, it can. P03CE is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P03CE to fix?
Difficulty: medium. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will P03CE clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.