What does injector circuit open code mean?

An injector circuit open code means the engine control module has detected an open or broken path in the electrical circuit that powers one or more fuel injectors, preventing current from reaching the injector. This is commonly recorded as P0200 (Injector Circuit Malfunction) or cylinder-specific variants like P0201–P0204, depending on the engine. It often triggers a check engine light and can cause rough running or misfires.

What the code indicates

At its core, modern engines rely on the engine control unit (ECU) to energize each fuel injector on cue. An open circuit means there is no complete electrical path for the injector coil to energize, so the injector cannot spray fuel when commanded. Without fuel delivery, the affected cylinder misfires or runs lean, which can degrade performance and emissions controls.

• Open or broken wiring in the injector circuit


• Faulty injector with an internal open coil


• Loose, corroded, or damaged connectors or pins


• Blown fuse or failed injector relay that interrupts power or ground


• Poor ECU ground or supply voltage issue


• Rarely, an ECU fault or a software/ Calibration issue

If you see this code, the root cause is most often found in wiring, connectors, or the injector itself. A professional diagnostic should confirm the exact location of the break or fault.

Common causes

Diagnosticians typically look for problems in the physical injector circuit path. The following are the most frequent culprits when an injector circuit is reported as open:

• Damaged or frayed wiring in the injector harness


• Corroded or loose connector pins at the injector or ECU


• Faulty injector with an internal open coil

Addressing the issue usually involves electrical inspection and component testing. In some cases, the fault is intermittent and requires monitoring live data to catch the moment the circuit opens.

How to diagnose

Diagnostics typically follow a structured approach to determine whether the problem is the injector, the wiring, or the control module.

1. Verify the code with a reliable OBD-II scanner and review freeze-frame data.


2. Check all related fuses and relays supplying power to the injectors.


3. Inspect injector connectors and wiring for visible damage, corrosion, or loose pins.


4. Measure the injector's resistance with a multimeter and compare to the manufacturer’s specification.


5. Perform a current/voltage test while the engine is cranking to confirm whether the injector is receiving control signals.


6. Swap injector circuits or injectors between cylinders to see if the problem follows the part or stays with the circuit.


7. Inspect engine grounds and the PCM/ECU grounding paths; verify stable voltage supply to the injector driver circuits.


8. If needed, perform more advanced tests or consult the manufacturer service data for OEM-specific procedures.

Following these steps helps isolate whether the issue is a bad injector, wiring fault, connector problem, or a defective control module. In many cases, repairing wiring or replacing a faulty injector resolves the code.

What to expect in terms of driveability

Injector circuit open codes often present with noticeable drivability problems, especially at idle or under load. Symptoms may include:

• Rough idle or stumble


• Engine misfire or reduced power


• Increased fuel consumption or rough acceleration


• Check Engine Light with a pending or stored code


• Possible diagnostics trouble that worsens when the engine is under load

Continued driving with an unresolved injector circuit issue can lead to further catalyst damage or elevated emissions, so it’s advisable to diagnose and repair promptly.

Repair options

Repair choices depend on the confirmed root cause. Typical remedies include:

1. Repair or replace damaged wiring or connectors in the injector circuit


2. Replace a faulty injector with an open coil


3. Replace a blown fuse or faulty injector relay and verify circuit continuity


4. Repair ECU grounding or power supply issues, if the fault lies there


5. Re-test the system after repair to confirm the code clears and drivability returns to normal

Because injector circuits are critical to proper engine operation, professional diagnosis is recommended if standard checks do not identify a clear fault. In some cases, the issue may be intermittent or require OEM-specific procedures.

Summary

An injector circuit open code signals an interruption in the electrical path to one or more fuel injectors, preventing proper fuel delivery. Most common causes are wiring damage, bad connectors, injector faults, or a blown fuse/relay. A methodical diagnostic approach—checking wiring, connectors, injector resistance, and control signals—helps determine whether the fix is a wiring repair, injector replacement, or ECU-related repair. Prompt attention can restore engine performance and protect the catalytic system.

Related notes

Codes and exact terminology can vary by manufacturer and scanner. In some vehicles, the generic P0200 family may be paired with cylinder-specific subcodes (P0201–P0204, etc.) or described as “Injector Circuit Open” by OEM-specific diagnostic tools. Always refer to the vehicle’s service information for exact test procedures and specifications.

Final takeaway

If your check engine light is on and a code indicates an injector circuit open, start with a visual check of wiring and connectors, then verify fuses and relays. If the issue persists, diagnostic testing of injector resistance and circuit continuity is essential to pinpoint the fault before replacing parts.

Note: For safety and accuracy, consider professional service if you are not equipped to perform electrical diagnostics on automotive fuel systems.

Can you drive with an injector fault?

No, it is not recommended to drive with a bad fuel injector as it can lead to various issues, from poor performance to severe engine damage and safety hazards. The most significant risks include engine misfires, a damaged catalytic converter, and potentially catastrophic engine failure like hydrolocking, so it is best to get the vehicle inspected and repaired immediately. 
This video explains the risks of driving with a bad fuel injector: 49sMercie J Auto Care, llcYouTube · Nov 12, 2025
Risks of driving with a bad fuel injector

• Poor engine performance: You may experience engine misfires, stalling, and a decrease in fuel efficiency. The engine may also feel rough and vibrate. 
• Damage to other components: An incorrect air-fuel mixture can cause the catalytic converter to overheat and fail, which is an expensive repair. Driving with a leaking injector can also dilute the engine oil. 
• Catastrophic engine damage: If an injector leaks too much fuel, it can cause the engine to hydrolock. This occurs when liquid fuel fills the cylinder, and because liquids are incompressible, it can lead to bent connecting rods and other severe internal engine damage. 
• Safety concerns: External fuel leaks from a bad injector can create a fire hazard. 

What you should do instead

• Avoid driving the vehicle if possible. 
• If you must drive, do so for the shortest distance necessary to get to a repair shop. 
• Have the car inspected and repaired by a professional mechanic as soon as possible to prevent further damage. 

You can watch this video to see what happens when an engine hydro locks: 51sMercie J Auto Care, llcYouTube · Jul 1, 2024

What does injector circuit open cylinder mean?

What does the P0201 Code Mean? Diagnostic trouble code (DTC) code P0201 stands for “Cylinder 1 Injector Circuit/Open.” It indicates a potential problem with the #1 Fuel Injector Circuit, like a broken wire, loose terminal, burned out injector coil, or some other circuit interruption issue.

What can cause an open circuit on a fuel injector?

An open injector circuit is caused by a break in the electrical path to the fuel injector, most commonly due to a defective fuel injector, a broken or loose wire, or a faulty connection. Other causes can include blown fuses, a bad fuel injector relay, or a malfunctioning Powertrain Control Module (PCM).
 
Causes of an open injector circuit 
This video explains the causes and fixes for an open injector circuit: 1mHVAC Mechanic YouTube · Oct 2, 2024

• Defective fuel injector: The injector itself can fail, with a common failure mode being an open coil inside the injector. 
• Damaged or loose wiring: A wire in the harness can break, or a connector can become loose, corroded, or have a broken terminal. 
• Faulty components: A blown fuse or a failing fuel injector relay can interrupt the circuit. 
• PCM issue: In rare cases, the PCM's internal driver or the wiring to it can fail. 
• Corrosion: Corrosion in the wiring harness or connectors can break the electrical connection. 

How much does it cost to repair an injector circuit open?

The average cost for a Fuel Injector Replacement is between $763 and $966. Labor costs are estimated between $278 and $408 while parts are priced between $485 and $558. This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.