P0201 Code: Injector Circuit Malfunction - Cylinder 1
🟠 Moderate severity · drivable
Drivable short-term, but cylinder 1 may misfire and unburned fuel can damage the catalytic converter — fix it soon.
What P0201 means
The engine computer has detected an electrical fault in the fuel injector circuit for cylinder 1, so it can't control that injector properly. P0201 is an electrical/circuit fault, not a fuel-delivery problem — and because cylinder 1 isn't getting the right fuel, this code often shows up alongside a cylinder 1 misfire (P0301).
Symptoms
- Check engine light on (may flash)
- Rough idle or misfire on cylinder 1
- Loss of power
- Poor fuel economy
Common causes
- most common: Faulty fuel injector on cylinder 1 (internal electrical fault)
- common: Damaged wiring or a loose connector at the cylinder 1 injector
- less common: Injector driver failure inside the engine computer (PCM)
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Test the cylinder 1 injector circuit with a noid light | Yes | $10–30 |
| Swap the cylinder 1 injector with another cylinder to see if the fault follows it | Mechanic | $100–300 |
| Replace the cylinder 1 fuel injector | Mechanic | $100–300 |
| Repair damaged injector wiring or connector | Mechanic | $50–150 |
Frequently asked questions
Is P0201 an electrical fault or a fuel problem?
Electrical. P0201 means the injector circuit itself isn't working — the computer can't command the injector. It typically causes a cylinder 1 misfire (P0301) as a knock-on effect.
What's a noid light and why use one?
A noid light plugs into the injector connector and flashes when the computer commands the injector. If it doesn't flash, the circuit or computer driver is at fault, not the injector itself.
Can I drive with a P0201 code?
Briefly, but cylinder 1 may misfire and dump unburned fuel into the catalytic converter, so fix it soon.
Related codes
P0301
P0301 Code: Cylinder 1 Misfire Detected
P0200P0200 Code: Injector Circuit Malfunction
P0261P0261 Code: Cylinder 1 Injector Circuit Low
Related guide: The 10 Most Common Check Engine Codes →
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.