P0264 – Meaning, Symptoms, Causes & How to Fix It

P0264 is a fuel-injector related trouble code that can make your engine run rough, waste fuel, and potentially damage internal components if you ignore it. This code points specifically to a problem with the fuel injector circuit for cylinder 2, so you’re dealing with an issue that affects one cylinder rather than the whole engine. In this guide, you’ll learn what P0264 means, the most common causes, symptoms to watch for, how a mechanic would diagnose it, possible repairs, and what it might cost to fix on your vehicle.

What Does P0264 Mean?

P0264 is an OBD-II diagnostic trouble code that stands for “Cylinder 2 Injector Circuit Low.” Your engine control unit (ECU) monitors the electrical circuit that controls each fuel injector. When the ECU detects that the voltage or current in the injector circuit for cylinder 2 is lower than expected, it stores code P0264 and usually turns on the check engine light.

In simple terms, the ECU is seeing an electrical problem with the injector for cylinder 2. That could be a failing injector, damaged wiring, poor connection at the injector plug, or in rarer cases, an issue inside the ECU or driver circuit.

Quick Reference

Code: P0264
Definition: Cylinder 2 Injector Circuit Low
System: Fuel injection / engine management
Severity: Moderate to serious (can cause misfire and engine damage over time)
Common Fixes: Repair wiring, replace injector, clean connectors, occasionally ECU repair

Real-World Example / Field Notes

In the shop, P0264 often comes in as a rough idle complaint or a flashing check engine light under load. A typical case: a sedan with 120k miles, customer says it “shakes at stoplights” and fuel economy dropped. Scan tool shows P0264 plus a misfire on cylinder 2. A quick wiggle test on the injector connector makes the idle change. Pull the connector and find green corrosion on the pins from years of moisture. Clean and tighten the terminals, clear the codes, and the engine smooths right out. In other cases, the injector coil itself is open or shorted and needs replacement.

Symptoms of P0264

Check engine light: Steady or flashing MIL, sometimes with additional misfire codes.
Rough idle: Engine may shake or feel uneven, especially when stopped in gear.
Loss of power: Noticeable lack of acceleration, particularly when climbing hills or passing.
Engine misfire: Hesitation, stumbling, or a “chugging” feel from one dead or weak cylinder.
Poor fuel economy: You may see increased fuel consumption due to inefficient combustion.
Fuel smell from exhaust: If the injector is stuck open, you might smell raw fuel or see black smoke.
Hard starting: Extended cranking or needing to press the throttle to start in some cases.
Engine vibration: Extra vibration through the steering wheel, seat, or shifter at certain RPMs.

Common Causes of P0264

Most Common Causes

Faulty cylinder 2 fuel injector: Internal coil failure, short, or open circuit in the injector itself.
Damaged injector wiring: Chafed, broken, or shorted wires between the injector and ECU harness.
Corroded or loose injector connector: Moisture, oil, or dirt causing high resistance and low voltage.
Poor electrical ground: Weak or corroded engine ground points affecting injector circuit operation.
Previous engine work errors: Harness pinched, misrouted, or not fully plugged in after repairs.

Less Common Causes

ECU driver failure: Internal fault in the ECU’s injector driver for cylinder 2 causing low output.
Short to voltage or ground in harness: Harness rubbed through on brackets or engine components.
Excessive resistance in circuit: Poor splices, aftermarket add-ons, or internal harness corrosion.
Low system voltage: Weak battery or charging system problems exaggerating injector circuit issues.
Connector pin damage: Bent, pushed-back, or spread terminals at the injector or ECU plug.

Diagnosis: Step-by-Step Guide

To diagnose P0264 properly, you’ll want a quality scan tool, a digital multimeter (DMM), basic hand tools, and access to wiring diagrams for your specific vehicle. An injector test light or noid light and, ideally, an oscilloscope make the job easier, but they’re not strictly required for a basic diagnosis.

Confirm the code and check for companions. Use a scan tool to read all stored and pending codes. Look for related misfire codes (like P0302) or other injector circuit codes that might point to a broader issue.
Inspect cylinder numbering. Verify which cylinder is #2 on your engine. Manufacturers number cylinders differently, and misidentifying the cylinder is a common mistake.
Visual inspection of injector and harness. With the engine off, inspect the cylinder 2 injector connector and wiring. Look for cracked insulation, oil saturation, rubbing points, or broken clips. Gently tug on the harness and connector.
Check connector condition. Unplug the injector and inspect the terminals. Look for corrosion, moisture, or bent pins. Clean with electrical contact cleaner and apply a small amount of dielectric grease if recommended.
Measure injector coil resistance. Using a DMM, measure the resistance across the injector terminals. Compare your reading to the spec in the service manual. A reading that is open (infinite), very low, or far out of range means the injector is faulty.
Check for power and ground at injector. With the key on (engine off), verify that you have proper voltage on the injector power feed and a good ground or ECU-controlled side (depending on design). A test light or DMM can be used here.
Perform a wiggle test. While monitoring the injector circuit with a scan tool, test light, or DMM, gently move the harness and connector. If readings or engine behavior change, you likely have an intermittent wiring or connector issue.
Swap injectors (if accessible). If resistance is borderline but not obviously bad, swap the cylinder 2 injector with another cylinder (for example, cylinder 3). Clear codes and see if the code or misfire follows the injector. If P0264 changes to a different cylinder, the injector is the culprit.
Check ECU driver (advanced). If wiring and injector test good, an experienced technician may use an oscilloscope or Mode $06 data to check injector command signals and misfire counts. If the ECU isn’t properly driving the injector, internal ECU failure is possible.
Recheck after repairs. After any repair or part replacement, clear codes, perform a road test, and re-scan. Make sure P0264 does not return and that fuel trims and misfire counters look normal.

Pro tip: Always fix any obvious wiring or connector issues before replacing the injector. Many P0264 cases are due to simple harness damage or corrosion, not the injector itself.

Possible Fixes & Repair Costs

Typical repairs for P0264 focus on restoring proper injector circuit operation to cylinder 2. Costs vary based on vehicle make, engine layout, and how difficult the injector is to access.

Repair or replace wiring/connectors: Splicing in new wire, repairing chafed sections, or replacing a damaged connector. Expect roughly $100–$300 depending on labor time and parts availability.
Replace cylinder 2 fuel injector: New or remanufactured injector plus labor. On many vehicles, this runs about $200–$500 per injector. Direct-injection systems or V-engine layouts under intake manifolds can be higher.
Injector cleaning (if slightly restricted): Professional on-car cleaning or bench cleaning can cost $80–$200, but this only helps if the injector is mechanically dirty, not electrically faulty.
ECU repair or replacement: Rare but expensive. Depending on the vehicle, you might see $600–$1,500 including programming.

Overall, most P0264 repairs fall in the $150–$600 range when it’s just the injector or wiring. Costs rise if intake manifolds must be removed, if multiple injectors are replaced, or if a dealer-only ECU is required.

Can I Still Drive With P0264?

You can usually drive short distances with P0264, but it’s not recommended to ignore it. A misfiring or under-fueled cylinder 2 can cause rough running, poor acceleration, and higher fuel consumption. If the injector is stuck open, you risk washing down the cylinder walls with fuel, thinning the oil, and damaging the catalytic converter. If the check engine light is flashing or the engine feels very rough, you should avoid driving and have the vehicle towed to prevent further damage.

What Happens If You Ignore P0264?

Ignoring P0264 can turn a relatively simple injector or wiring repair into a much bigger problem. Long-term misfire on cylinder 2 can overheat and damage the catalytic converter, foul spark plugs, contaminate engine oil with fuel, and in severe cases lead to piston, ring, or valve damage. You’ll also live with poor performance and fuel economy until the issue is fixed.

Last updated: January 22, 2026

Key Takeaways

P0264 means the ECU detects low voltage or current in the injector circuit for cylinder 2.
Most causes are electrical: bad injector, damaged wiring, or corroded connectors.
Common symptoms include rough idle, misfire, loss of power, and poor fuel economy.
Proper diagnosis involves checking wiring, injector resistance, power/ground, and sometimes swapping injectors.
Typical repair costs range from about $150–$600, more if ECU or hard-to-reach injectors are involved.
Driving too long with P0264 can damage the catalytic converter and engine components.

Vehicles Commonly Affected by P0264

P0264 can appear on almost any OBD-II equipped vehicle, but it’s more frequently seen on higher-mileage models and engines where the injector harness runs close to hot or vibrating components. You’ll often find this code on:

Ford trucks and SUVs (F-150, Expedition, Explorer) with V6 and V8 engines.
GM/Chevrolet vehicles (Silverado, Tahoe, Suburban, Malibu) with port or direct injection systems.
Dodge/Ram/Chrysler models, especially V6 and HEMI V8 engines.
Honda and Acura 4-cylinder and V6 engines with aging injector connectors.
Toyota and Lexus sedans and SUVs where wiring corrosion or rodent damage is common.
Volkswagen/Audi direct-injection engines that use high-pressure injectors and complex harnesses.

FAQ

Can P0264 go away on its own?

Sometimes P0264 may disappear temporarily if the issue is intermittent, like a loose connector or vibration-sensitive wire. However, the underlying problem usually returns. If the code appeared once, you should still inspect the injector and wiring before assuming it “fixed itself.”

Is P0264 always a bad injector?

No, P0264 is not always caused by a bad injector. Wiring damage, corroded connectors, poor grounds, or even ECU driver issues can trigger this code. That’s why testing resistance, power, and ground, and sometimes swapping injectors, is important before buying a new part.

Can I clean the injector to fix P0264?

Cleaning can help if the injector is mechanically dirty or partially clogged, but P0264 is an electrical circuit low code. If the injector coil is failing or the wiring is damaged, cleaning won’t solve it. Use cleaning as a supplement, not a substitute, for proper electrical diagnosis.

How serious is P0264 compared to other codes?

P0264 is more serious than a simple emissions code but less critical than some safety-related faults. It directly affects how your engine runs. Left alone, it can cause long-term damage to the catalytic converter and engine, so you should treat it as a priority repair.

Can low battery voltage cause P0264?

Low system voltage from a weak battery or failing alternator can exaggerate injector circuit issues and, in rare cases, contribute to codes like P0264. However, most of the time there is a specific problem with the injector, wiring, or connector on cylinder 2 that needs to be addressed.

P0264 – Cylinder 2 Injector Circuit Low