OBD2 code P0203: Cylinder 3 Injector A Circuit/Open
P0203 reports an electrical fault, mainly an open circuit, in the injector circuit of cylinder 3.
Detected Root Component
Injector
Technical Component Diagrams
Injector Layout
Diag Expert technical diagram
Injector Connector
Diag Expert technical diagram
Observed Symptoms
- Check engine light on
- Misfire and rough running, misfire code P0303
- Loss of power, rough idle
- Limp mode possible on diesel and direct injection
Possible Causes
- Connector at the cylinder 3 injector loose, corroded or with a broken or pushed-back pin
- Injector coil open
- Wire between module and injector open or chafed (heat, rodents)
- Injector supply missing (fuse, relay) – then usually several cylinders at once
- Driver stage in the engine module faulty
Tools Required
Interactive Diagnostic
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Parts likely to be the cause (Injecteur)
Injecteur
Photo d'illustration : Injecteur
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Frequently asked questions about code P0203
What does code P0203 mean? ▾
OBD2 code P0203: Cylinder 3 Injector A Circuit/Open. P0203 reports an electrical fault, mainly an open circuit, in the injector circuit of cylinder 3.
What are the symptoms of code P0203? ▾
Code P0203 may cause: Check engine light on, Misfire and rough running, misfire code P0303, Loss of power, rough idle, Limp mode possible on diesel and direct injection. The intensity of these symptoms varies depending on the vehicle and driving conditions.
What causes code P0203? ▾
The most common causes of code P0203 are: Connector at the cylinder 3 injector loose, corroded or with a broken or pushed-back pin, Injector coil open, Wire between module and injector open or chafed (heat, rodents), Injector supply missing (fuse, relay) – then usually several cylinders at once. A proper OBD2 diagnostic will pinpoint the exact cause.
Is it serious to drive with code P0203? ▾
Code P0203 has moderate severity (Warning). Short-term driving remains possible, but a prompt check is recommended to prevent worsening.
How do I fix code P0203? ▾
Start by reading the code with an OBD2 scanner, then follow the interactive decision tree on this page. Priority causes to check: Connector at the cylinder 3 injector loose, corroded or with a broken or pushed-back pin, Injector coil open, Wire between module and injector open or chafed (heat, rodents), Injector supply missing (fuse, relay) – then usually several cylinders at once. Difficulty: Medium · Estimated time: 30-60min.