P0203: Injector circuit malfunction - cylinder 3
Flashing light? Stop driving now. Steady light? Drive gently to a mechanic soon.
Can I drive with P0203?
Flashing light? Stop driving now. Steady light? Drive gently to a mechanic soon. If the check engine light is steady, drive gently to a mechanic soon. If the check engine light is FLASHING, stop driving. Unburned fuel can destroy the catalytic converter.
What does P0203 mean?
P0203 stands for Injector Circuit/Open - Cylinder 3.
Symptoms you may notice
- Engine shaking or stumbling under acceleration
- Noticeable power loss and sluggish response
- Flashing or steady check engine light
- Strong fuel odor from the exhaust pipe
How much does it cost to fix?
Repair costs for code P0203 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Defective fuel injector 3
- Unplugged harness connector
- Harness short or open
- ECU hardware fault
What to do next
- Observe your check engine light: if it is FLASHING, stop driving now to avoid catalytic converter damage.
- If the check engine light is STEADY, drive gently to a mechanic soon without hard acceleration or towing.
- Inspect the spark plugs, ignition coils, and fuel injector connectors for faults.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P0203 means cylinder 3 injector cannot be activated. Treat as an urgent repair.