P0203 code meaning
Cylinder 3 Injector A Circuit/Open
Powertrain system Generic code P02xx codes Check engine light
What P0203 means
P0203 reports an electrical fault, mainly an open circuit, in the injector circuit of cylinder 3. The engine module watches each injector output: GM flags an open circuit at an impedance of 200 kΩ or more – on direct injection and diesel engines in 10 of 20 or 5 of 10 samples and with the warning light in the first trip, on some port-injected engines only after two trips. Ford's port injection reads a fault bit from the driver chip that covers open, short to ground and short to voltage alike; Ford diesels report only the open circuit here and shorts as P0267/P0268. On direct injection the affected injector is switched off; the cylinder misfires.
P0203 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0203
- Check engine light on
- Misfire and rough running, misfire code P0303
- Loss of power, rough idle
- Limp mode possible on diesel and direct injection
Common causes of P0203
- Most likelyConnector at the cylinder 3 injector loose, corroded or with a broken or pushed-back pin
- PossibleInjector coil open
- PossibleWire between module and injector open or chafed (heat, rodents)
- Less likelyInjector supply missing (fuse, relay) – then usually several cylinders at once
- Less likelyDriver stage in the engine module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injector cylinder 3Injector wiringEngine control module
What each part of P0203 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 03 | The exact fault in that area. |
What to do next
- Note P0203 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 P0203
What does P0203 mean?
P0203 means "Cylinder 3 Injector A Circuit/Open". P0203 reports an electrical fault, mainly an open circuit, in the injector circuit of cylinder 3. It is a generic code, so it means the same on every make.
Is it safe to drive with P0203?
Drive gently and only to a workshop. With P0203 the car can go into limp mode (reduced power) to protect itself.
Will P0203 fail an emissions test?
Yes, it can. P0203 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 P0203 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0203 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.