P0201 is a generic OBD-II powertrain fault code that means Injector Circuit/Open Cylinder 1. The ECM/PCM has detected an electrical problem in the fuel injector circuit for Cylinder 1.
P0201 may be encountered on applicable vehicles from Honda, Nissan, and Jeep. The injector type, wiring arrangement, control strategy, and diagnostic specifications can vary depending on the engine and model year.
Fault Code Description
P0201 = Injector Circuit/Open Cylinder 1.
Code type: Generic OBD-II Powertrain Code.
Likely fault location: Cylinder 1 fuel injector, injector connector, injector wiring, injector power supply, injector control circuit, or in rare cases the ECM/PCM injector driver.
The word Open refers to an interruption or abnormal electrical condition in the injector circuit. It does not automatically mean that the injector itself is defective.
What Does P0201 Mean?
The ECM/PCM controls the fuel injector for Cylinder 1 by sending an electrical command through the injector circuit. The control module also monitors the circuit for an expected electrical response.
If the circuit becomes open, loses its required electrical connection, develops excessive resistance, or otherwise fails the expected injector monitoring conditions, the ECM/PCM may store P0201.
Symptoms of P0201
- Check Engine Light.
- Engine misfire.
- Rough or unstable idle.
- Hesitation during acceleration.
- Loss of engine power.
- Poor fuel economy.
- Hard starting.
- Engine vibration.
- Engine may stall in severe cases.
- Flashing Check Engine Light when a severe misfire is present.
Common Causes of P0201
- Faulty Cylinder 1 fuel injector.
- Open injector circuit.
- Broken injector control wire.
- Damaged injector connector.
- Loose or corroded connector terminal.
- High resistance in the injector circuit.
- Loss of injector power supply.
- Damaged wiring near the engine.
- Incorrect previous wiring repair.
- ECM/PCM injector driver fault.
- Fuel contamination affecting injector operation.
How to Fix P0201
1. Scan the Vehicle
Confirm P0201 with a professional scan tool and check for additional injector, misfire, fuel-system, or electrical codes.
2. Identify Cylinder 1
Confirm the location of Cylinder 1 using the manufacturer's service information. Cylinder numbering can vary between engine configurations.
3. Inspect the Injector Connector
Inspect the Cylinder 1 injector connector for loose terminals, corrosion, damaged locking tabs, contamination, or poor electrical contact.
4. Check Injector Power and Control
Use the vehicle-specific wiring diagram to identify the injector power and control circuits. Verify the expected voltage and control signal according to the manufacturer's testing procedure.
5. Test Injector Resistance
Where permitted by the manufacturer, measure the resistance of the Cylinder 1 injector and compare it with the specified value. Do not apply a generic resistance specification to every injector type.
6. Check Injector Wiring
Inspect the complete circuit between the injector and ECM/PCM. Look for broken wires, damaged insulation, high resistance, short circuits, or wiring affected by engine heat and vibration.
7. Check the ECM/PCM Driver
If the injector, connector, power supply, and wiring are verified, test the injector control driver according to the manufacturer's service procedure before considering ECM/PCM replacement.
P0201 Diagnostic Signal Flow
↓
Cylinder 1 Injector Control Circuit
↓
Injector Connector
↓
Cylinder 1 Fuel Injector
↓
Fuel Delivery
↓
Cylinder 1 Combustion
P0201 OBD Live Data
Use OBD live data to check engine RPM, misfire counters, fuel trims, and other available cylinder or injector-related parameters. If Cylinder 1 shows significantly different behavior from the other cylinders, further testing of the injector circuit is justified.
Live data should be combined with electrical testing because P0201 is primarily an injector circuit fault. A normal-looking scan-tool reading does not rule out an intermittent wiring or connector problem.
P0201 Honda, Nissan and Jeep
P0201 has the same generic OBD-II definition on applicable Honda, Nissan, and Jeep vehicles, but the actual injector circuit and diagnostic procedure can vary significantly between engines.
P0201 Honda
On applicable Honda vehicles, check the Cylinder 1 injector connector, injector wiring, power supply, and control circuit. Compare injector operation and cylinder-specific data where available.
Use the exact Honda engine wiring diagram and injector specifications before replacing the injector.
P0201 Nissan
On applicable Nissan vehicles, inspect the Cylinder 1 injector circuit for an open connection, poor terminal contact, wiring damage, or abnormal injector resistance.
Check the injector power and ECM control signal according to the specific Nissan engine service procedure.
P0201 Jeep
On applicable Jeep vehicles, check the Cylinder 1 injector connector and wiring, then verify injector power and the ECM control circuit.
A wiggle test can help identify an intermittent connection caused by engine vibration or damaged wiring.
The important difference between these manufacturers is the specific injector design and circuit configuration, not the basic P0201 definition. Always use vehicle-specific service information for the final electrical tests.
Is P0201 Serious?
P0201 can be serious if Cylinder 1 is not receiving the correct amount of fuel and the engine is misfiring. Severe misfires can cause poor drivability and may damage the catalytic converter on applicable gasoline engines.
Can I Drive With P0201?
Limited driving may be possible if the engine is running normally, but the fault should be diagnosed promptly. If the Check Engine Light is flashing, the engine is severely misfiring, or there is significant loss of power, avoid continued driving.
P0201 Repair Cost
- Electrical diagnosis: approximately $50–$150+.
- Injector wiring repair: approximately $50–$250+.
- Fuel injector replacement: approximately $100–$500+ depending on the vehicle.
- ECM/PCM diagnosis or repair: can cost considerably more.
These are general estimates only. Actual costs depend on the vehicle, engine, injector type, parts prices, and labor rate.
Common Repair Mistakes
- Replacing the injector without testing the circuit.
- Ignoring the injector connector.
- Failing to verify injector power.
- Ignoring wiring damage near the engine.
- Using the wrong cylinder numbering.
- Replacing the ECM/PCM before testing the injector circuit.
- Ignoring related misfire codes.
Related Codes
- P0200 – Injector Circuit Malfunction.
- P0202 – Injector Circuit/Open Cylinder 2.
- P0203 – Injector Circuit/Open Cylinder 3.
- P0204 – Injector Circuit/Open Cylinder 4.
- P0301 – Cylinder 1 Misfire Detected.
FAQ About P0201
What does P0201 mean?
P0201 means Injector Circuit/Open Cylinder 1. The ECM/PCM has detected an abnormal electrical condition in the fuel injector circuit for Cylinder 1.
How do I fix P0201?
Confirm Cylinder 1, inspect the injector connector and wiring, test injector power and control, measure injector resistance where applicable, and verify the ECM/PCM control circuit before replacing components.
Can a bad injector cause P0201?
Yes. A defective Cylinder 1 injector can trigger P0201, but the injector should not be blamed until its electrical circuit and connector have been tested.
Can P0201 cause a misfire?
Yes. If Cylinder 1 does not receive the correct injector command or fuel delivery, the cylinder can misfire and cause rough running, hesitation, and loss of power.
What should I check first with P0201?
Start with the stored codes and freeze-frame data, then identify Cylinder 1 and inspect its injector connector and wiring. Electrical testing should follow the manufacturer's wiring diagram and specifications.
Does P0201 mean the ECM is bad?
No. An ECM/PCM failure is possible but relatively less common than an injector, connector, wiring, or power-supply problem. The complete circuit should be tested before condemning the control module.
Is P0201 the same on Honda, Nissan and Jeep?
The base code definition is generic, but the injector circuit, wiring layout, injector specifications, and diagnostic procedure can differ between Honda, Nissan, Jeep, and different engine families.
Final Takeaway
The key to P0201 is to treat it as a Cylinder 1 injector circuit fault, not automatically as a failed injector. The most reliable diagnosis combines scan-tool data with direct electrical testing of the injector, connector, wiring, power supply, and ECM/PCM control circuit.
For applicable Honda, Nissan, and Jeep vehicles, always identify the exact engine and Cylinder 1 location before testing. Manufacturer-specific wiring diagrams and specifications should be used to determine whether the fault is inside the injector or somewhere else in the circuit.