P0201: The fuel injector circuit for cylinder 1 has a fault
Injector Circuit Malfunction -- Cylinder 1
There is a fault in the cylinder 1 fuel injector circuit, which causes a misfire. Get it checked today. If the light is flashing, stop driving: raw fuel overheats the catalytic converter.
Stop driving and get help if
- The check engine light is flashing
- The temperature gauge runs high, or you see steam (overheating)
- The car loses power, hesitates badly or stalls
- You smell burning or see smoke
- A brake warning light comes on, or the brakes feel different
Pull over as soon as you can, turn the engine off, and call a tow or roadside help.
What it means
P0201 means the PCM detected an electrical fault in the injector circuit for cylinder 1. This is a circuit code, not a flow code. It means the computer cannot confirm normal resistance or current when it commands the injector to fire. The cylinder may be misfiring as a result. The injector itself could be dead, or the wiring between the PCM and the injector could be open or shorted. A misfire code like P0301 often appears alongside P0201, which is the expected result of a cylinder that is not receiving fuel.
Common causes
- Open or short in the injector wiring harnessHeat, chafing, and rodent damage are common. Check the harness before replacing the injector.
- Failed fuel injectorThe injector solenoid coil has burned out. Resistance will be out of spec when measured with a multimeter.
- Corroded or damaged injector connectorThe injector harness connector corrodes from engine heat and moisture over time.
- Failed injector driver in the PCMRare, but the PCM output driver for the injector can fail. Usually only after other causes are ruled out.
What the fix could involve
From the cheaper fix to the bigger one. Prices depend on your car, your area and the shop, so ask for a written quote that names the part and the labor before you approve it.
- Wiring repair or connector replacement
- Fuel injector replacement (single)
- PCM diagnosis and replacement
Symptoms
- Check engine light on, steady or flashing
- Rough idle and engine shake
- Loss of power and hesitation
- Possible P0301 (cylinder 1 misfire) stored alongside this code
- Worse fuel economy
What to do next
Measure injector resistance with a multimeter at the injector connector. A healthy injector reads 10 to 18 ohms for most port injectors, and much lower (about 1 to 5 ohms) for direct injection. If resistance is out of spec, replace the injector. If resistance is fine, the fault is in the wiring or PCM driver. Swap injector connectors with an adjacent cylinder if possible to distinguish wiring from injector failure.
Lewis reads P0201 alongside any misfire codes for cylinder 1, so you can confirm the injector fault is causing a misfire before you start pulling connectors. Get Lewis on the App Store or Google Play.
Related codes
FAQ
- P0201 and P0301 both stored -- which do I fix first?
- They are linked. P0201 is the circuit fault causing the misfire that triggers P0301. Fix the injector circuit and P0301 should clear on its own.
- Can I drive with a dead injector?
- It is not something to rely on. A dead injector means a damaging misfire on that cylinder. Get it checked today. If the check engine light is flashing, stop now and have it towed.
- Do I need to replace all injectors at once?
- No, unless high mileage warrants it for preventive maintenance. Replacing the faulty one is the correct repair.
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