Bad or defective cylinder 1 fuel injector (both sources; OBD-Codes.com says this is usually the cause). Open or shorted wiring to the injector (OBD-Codes.com). Corroded or faulty wiring and connections (RepairPal). Plugged injector or dirt in the injector (RepairPal). Bad PCM (OBD-Codes.com), though RepairPal warns that replacing the injector or PCM when the real problem is wiring and connections is a common misdiagnosis. The sources lean differently: OBD-Codes.com points first to the injector, while RepairPal stresses checking wiring and connections before replacing the injector or PCM.

Repair damaged, open, shorted or corroded wiring or connectors in the cylinder 1 injector circuit (both sources). Replace the cylinder 1 fuel injector if it is out of spec, plugged, or the code follows it (both sources). Replace or repair the PCM only after the injector and wiring test good (OBD-Codes.com; RepairPal warns this is often misdiagnosed).

P0201⛽ Fuel injection / Injector circuitStop and fix promptly

P0201: Injector Circuit/Open, Cylinder 1 (Meaning, Causes, Fixes)

Q: What does P0201 mean?

P0201 means the engine computer has found a problem in the electrical circuit for the cylinder 1 fuel injector. The usual cause is a bad injector, but damaged, open or shorted wiring, corroded connectors, a plugged injector, or rarely the computer itself can set it. The powertrain control module (PCM) turns each fuel injector on and off using transistors that RepairPal calls drivers. OBD-Codes.com explains that when the injector is switched on the PCM expects the voltage on its control wire to be pulled low, close to zero, and when it is switched off it expects close to battery voltage. If the PCM doesn't see the expected voltage, or the circuit resistance is too high or too low, it sets P0201. RepairPal describes it as the PCM being unable to control the cylinder 1 fuel injector. The two sources name it slightly differently: OBD-Codes.com calls it Cylinder 1 Injector Circuit Malfunction and RepairPal calls it Injector Circuit/Open, Cylinder 1, but they describe the same fault. It is a generic OBD-II code, though repair steps vary by make and model. Sibling codes P0202 through P0212 cover the other cylinders, and P0200 is the general injector circuit code.

Q: Can I keep driving with P0201?

Stop and fix promptly. Get it diagnosed soon and don't ignore it. RepairPal rates P0201 Urgent, meaning it can cause severe damage or be unsafe. OBD-Codes.com says it will likely cause a misfire, rough running and poor acceleration. If the check engine light is flashing, the engine is shaking badly, or it loses power, keep driving to a minimum and have it checked, since a misfiring cylinder can damage other parts.

Reviewed 2026-10-22 · Based on 2 cited source(s)

What P0201 means

The powertrain control module (PCM) turns each fuel injector on and off using transistors that RepairPal calls drivers. OBD-Codes.com explains that when the injector is switched on the PCM expects the voltage on its control wire to be pulled low, close to zero, and when it is switched off it expects close to battery voltage. If the PCM doesn't see the expected voltage, or the circuit resistance is too high or too low, it sets P0201. RepairPal describes it as the PCM being unable to control the cylinder 1 fuel injector. The two sources name it slightly differently: OBD-Codes.com calls it Cylinder 1 Injector Circuit Malfunction and RepairPal calls it Injector Circuit/Open, Cylinder 1, but they describe the same fault. It is a generic OBD-II code, though repair steps vary by make and model. Sibling codes P0202 through P0212 cover the other cylinders, and P0200 is the general injector circuit code.

Severity: can I keep driving?

Stop and fix promptly

Get it diagnosed soon and don't ignore it. RepairPal rates P0201 Urgent, meaning it can cause severe damage or be unsafe. OBD-Codes.com says it will likely cause a misfire, rough running and poor acceleration. If the check engine light is flashing, the engine is shaking badly, or it loses power, keep driving to a minimum and have it checked, since a misfiring cylinder can damage other parts.

Common symptoms

Check engine light on (both sources)
Misfire and rough running or rough idle (both sources; RepairPal says only in some cases)
Poor acceleration (OBD-Codes.com)
Poor fuel economy in some cases (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Bad or defective cylinder 1 fuel injector (both sources; OBD-Codes.com says this is usually the cause)
Open or shorted wiring to the injector (OBD-Codes.com)
Corroded or faulty wiring and connections (RepairPal)
Plugged injector or dirt in the injector (RepairPal)
Bad PCM (OBD-Codes.com), though RepairPal warns that replacing the injector or PCM when the real problem is wiring and connections is a common misdiagnosis
The sources lean differently: OBD-Codes.com points first to the injector, while RepairPal stresses checking wiring and connections before replacing the injector or PCM

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read all stored codes and write down the freeze frame data. Misfire codes such as P0301 or P0300 often appear alongside P0201.
Visually check the cylinder 1 injector connector and wiring for damage, corrosion or broken wires (both sources).
With a digital multimeter, check the injector's resistance against your vehicle's spec, and check for at least 10 volts at the injector connector (OBD-Codes.com).
If you can't test the injector directly, OBD-Codes.com suggests swapping it with another cylinder's injector and seeing whether the code follows it, for example changing to P0202. If it moves, the injector is bad.
Avoid grounding PCM wires unless you are certain you have the correct wire; OBD-Codes.com warns not to attempt it if you're unsure.

Typical fixes

Repair damaged, open, shorted or corroded wiring or connectors in the cylinder 1 injector circuit (both sources)
Replace the cylinder 1 fuel injector if it is out of spec, plugged, or the code follows it (both sources)
Replace or repair the PCM only after the injector and wiring test good (OBD-Codes.com; RepairPal warns this is often misdiagnosed)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The check engine light is flashing or the engine runs very rough
Testing the PCM injector driver or tracing the circuit needs a wiring diagram and the factory specs
The injector and wiring test good and the code returns, which can point to the PCM
Several injector codes appear at once, which suggests a shared power feed or wiring problem rather than one injector

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Is P0201 serious?

Treat it as serious. RepairPal rates it Urgent, and OBD-Codes.com says it will likely cause a misfire and rough running. Get it diagnosed soon.

Is P0201 always a bad injector?

No. OBD-Codes.com says the injector is usually the cause, but wiring opens, shorts and corroded connectors can also set it, and RepairPal says replacing the injector or PCM when the problem is the wiring is a common misdiagnosis. Test before buying parts.

How can I tell if the injector is the problem?

OBD-Codes.com suggests checking the injector's resistance with a multimeter, or swapping it with another cylinder's injector. If the code moves to that cylinder, the injector is bad.

How much does it cost to fix P0201?

Neither source gives a repair cost. The price depends on whether it's wiring, the injector, or the PCM, so get a diagnosis or a written estimate before replacing parts.

Sources

Last reviewed 2026-10-22. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.