Faulty fuel injector for cylinder 1 (open or shorted internal coil); Damaged or corroded wiring harness connector at the injector; Broken, chafed, or shorted wire in the injector circuit between the computer and the injector; Loose or corroded ground connection for the injector circuit; Failed engine computer driver for that injector (rare but possible); Aftermarket or damaged injector with incorrect resistance; Contamination or debris in the injector causing electrical malfunction

DTC codes / P02xx · Fuel and air metering (injector circuits) / P0201

P0201Injector Circuit Malfunction - Cylinder 1

Q: What does code P0201 mean?

Injector Circuit Malfunction - Cylinder 1. P0201 means the engine computer has detected an electrical fault in the circuit that operates the fuel injector for cylinder 1. The computer monitors the injector driver circuit and sets this code when the current flow or voltage is outside the expected range, indicating an open, short, or excessive resistance in the wiring or injector itself.

P0201 means the engine computer has detected an electrical fault in the circuit that operates the fuel injector for cylinder 1. The computer monitors the injector driver circuit and sets this code when the current flow or voltage is outside the expected range, indicating an open, short, or excessive resistance in the wiring or injector itself.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illuminated check engine light, often with no other symptoms besides the warning light
Rough idle or misfire that is most noticeable when the engine is cold or under load
Noticeable loss of power and reduced fuel economy
Engine may stumble or hesitate during acceleration
In severe cases, the engine may run very poorly or stall, especially if other injectors are also affected
A faint fuel odor may be present if the injector is stuck open or leaking

Common causes, most likely first

Faulty fuel injector for cylinder 1 (open or shorted internal coil)
Damaged or corroded wiring harness connector at the injector
Broken, chafed, or shorted wire in the injector circuit between the computer and the injector
Loose or corroded ground connection for the injector circuit
Failed engine computer driver for that injector (rare but possible)
Aftermarket or damaged injector with incorrect resistance
Contamination or debris in the injector causing electrical malfunction

How to diagnose and fix it

Inspect the injector connector and wiring for obvious damage, corrosion, or loose pins; clean and reseat the connector
Measure the resistance of the cylinder 1 injector with a multimeter and compare to the manufacturer's specification
Check for battery voltage at the injector connector with the key on and engine off, using a test light or multimeter
Perform a continuity and short-to-ground test on the injector control wire from the computer to the injector
Swap the cylinder 1 injector with a known-good injector from another cylinder and see if the code moves, confirming the injector is at fault
If the injector and wiring test good, check the computer driver circuit with an oscilloscope or by testing with a noid light
Replace the faulty injector or repair the wiring as needed, then clear the code and verify the repair with a test drive

What a P0201 code does not always mean

A P0201 code does not automatically mean the injector itself has failed; wiring and connector problems are just as common and should be ruled out first.
The engine computer may set this code even if the injector still operates intermittently, so a visual inspection of the spray pattern is not a reliable test.
A misfire code for cylinder 1 (such as P0301) may be stored alongside P0201, but the presence of P0301 does not confirm the injector is the root cause without electrical testing.
Some vehicles use a shared power feed for multiple injectors, so a fault in that feed can set codes for several cylinders, not just cylinder 1.
After replacing an injector, the fuel trim and idle quality may take a short drive to relearn, so do not assume the repair failed if the light stays on briefly.

Can I keep driving with P0201?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration, towing, or long trips because a misfiring cylinder can overheat the catalytic converter and cause costly damage. If the engine is running very rough or stalling, stop driving and have it towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.