P0264 — Cylinder 2 Injector Circuit Low

powertrain (engine/transmission)

Is it safe to drive?

Repair promptly P0264 can allow the engine to run, but cylinder 2 misfire or hesitation should be corrected promptly. Avoid extended driving or highway operation if the engine is shaking, losing power, or producing a noticeable odor.

Typical symptoms

  • The check-engine light may illuminate with P0264 stored as a confirmed or pending code.
  • The engine may idle roughly, hesitate, or stumble because cylinder 2 is not receiving the commanded injector pulse correctly.
  • Cylinder 2 misfire information may appear in the scan data alongside P0264.
  • Cold starting, acceleration, and engine response may be noticeably uneven.
  • Fuel consumption and engine power may be reduced, especially when the cylinder 2 circuit fault is intermittent.

Common causes

  • P0264 indicates that the powertrain control module detected abnormally low voltage in the cylinder 2 injector driver circuit.
  • A short to ground, broken wire, or high-resistance connection in the cylinder 2 injector harness can trigger P0264.
  • Corrosion, damage, or poor terminal contact at the cylinder 2 injector connector may cause the low-circuit reading.
  • A failed or internally shorted cylinder 2 fuel injector is a possible cause of P0264.
  • A poor engine or injector ground and, less commonly, a defective powertrain control module injector driver can also set P0264.

How to diagnose with an OBD scanner

  1. Read P0264 with an OBD scanner Connect an ELM327 OBD scanner and read stored, pending, and freeze-frame data. Check whether P0264 is accompanied by cylinder 2 misfire counts or other fuel-system codes, and record the conditions under which the fault returns.
  2. Inspect the cylinder 2 injector wiring Disconnect the cylinder 2 injector connector and inspect the terminals, locking tab, harness insulation, and routing near hot or moving components. Look for corrosion, crushed wires, pin pushed back, or a short to ground.
  3. Perform circuit and voltage testing Using the vehicle wiring diagram, test the cylinder 2 injector circuit for continuity to ground, voltage at the connector during cranking, and excessive resistance or voltage drop under load. Confirm that the engine and injector grounds meet the specified resistance.
  4. Test the cylinder 2 injector Check the cylinder 2 injector for internal shorts and compare its resistance or current waveform with the manufacturer limits and other injectors. Do not rely on resistance alone; an injector can pass a static test while failing under operating conditions.
  5. Repair, clear, and verify P0264 Repair the damaged wire, connector, or ground, or replace the cylinder 2 injector if testing confirms failure. Clear the codes with the scanner, then verify that P0264 does not return and that cylinder 2 misfire counts remain normal.

Approximate repair cost

A typical independent-shop estimate for P0264 is about USD 150-650, depending on whether the repair involves wiring or connector work, diagnosis, or cylinder 2 injector replacement and labor. Figures are estimates and vary by region.

Common questions

Does P0264 always mean the cylinder 2 injector is bad?

No. P0264 identifies a low condition in the cylinder 2 injector circuit, and a wiring short, bad connector, poor ground, failed injector, or PCM driver can all produce it.

Is it safe to drive a vehicle with P0264?

Short trips to a repair shop may be possible if the engine runs smoothly, but avoid continued driving if P0264 causes severe misfire, shaking, power loss, or fuel odor.

What should I check first when P0264 is present?

Start with the cylinder 2 injector connector and harness, then test the circuit and grounds before condemning the injector or powertrain control module.

Will clearing the P0264 code repair the vehicle?

No. Clearing P0264 only erases the stored fault; the circuit, connector, injector, or control-module fault must be corrected and the code rechecked under operating conditions.

Modern engines rely on precise fuel metering through electrically controlled injectors. Each injector receives a signal from the engine control unit, which opens a solenoid valve for a calculated duration. When the control module detects that the voltage on the cylinder 2 injector circuit has dropped below the acceptable minimum, it stores diagnostic trouble code P0264. The module does not flag this condition based on a single anomalous reading — it must confirm the fault across multiple drive cycles under specific operating conditions before illuminating the check engine light.

The phrase "circuit low" indicates the wiring is being pulled toward ground when it should be carrying battery voltage or a pulsed signal. This can stem from a short to ground in the harness, a component failure inside the injector itself, or an interruption in the power supply feeding that specific cylinder. P0264 targets cylinder 2 exclusively, and cylinder numbering varies by engine orientation — on inline engines the count begins at the front pulley end, while V-configuration engines follow manufacturer-specific firing orders. The freeze frame data captured alongside the code shows engine load, RPM, coolant temperature, and vehicle speed at the moment of failure, which proves invaluable when recreating the fault during diagnosis.

When the ECU registers P0264, it typically adjusts fuel delivery to compensate, though compensation has limits. Without proper injector operation in cylinder 2, that cylinder misfires, unburned fuel enters the exhaust, and the engine runs roughly. Left unaddressed, the imbalance can damage catalytic converters and cause stalling under load.

Common Symptoms

  • Check Engine Light illuminated
  • Rough idle or visible engine hesitation during acceleration
  • Increased fuel consumption compared to normal driving
  • Extended cranking time or difficulty starting the engine
  • Fuel odor noticeable after shutdown
  • Reduced engine power under heavier loads

Common Causes

  • Broken or chafed wiring harness causing a short to ground on the cylinder 2 injector circuit
  • Failed cylinder 2 fuel injector with internal short or open winding
  • Missing or interrupted supply voltage to the cylinder 2 injector connector
  • Faulty fuel rail pressure sensor affecting injector pulse width calculations
  • Clogged or leaking fuel injectors restricting proper fuel delivery
  • Vacuum leaks downstream of the mass airflow sensor skewing the air-fuel mixture
  • Weak fuel pump or restricted fuel filter unable to maintain rail pressure
  • Contaminated or incorrect fuel grade causing injector performance issues

How to Diagnose

  1. Connect an OBD2 scanner and confirm P0264 is present in stored codes. Record the freeze frame data — this snapshot of engine conditions at the time of failure guides your diagnosis and helps reproduce the problem.
  2. Review all other stored and pending codes. Related electrical or fuel-pressure codes often point to the root cause. Check manufacturer technical service bulletins for known fixes specific to your make, model, and model year.
  3. Perform a visual inspection of the engine wiring harness around the cylinder 2 injector. Look for damaged insulation, rubbed-through wires contacting metal, corrosion at the connector pins, or loose connections.
  4. Backprobe the cylinder 2 injector connector and verify battery voltage is present on the power supply wire with the key on. Then check resistance from the signal wire to chassis ground — a reading near zero ohms confirms a short circuit in the harness.
  5. Measure fuel rail pressure with a gauge and compare against factory specifications at idle, part load, and full load. Pressure outside the specified range points toward pump, regulator, or filter issues.
  6. Monitor live data for short-term and long-term fuel trim values. Large positive trims indicate the ECU is adding fuel to compensate for a lean condition, while negative trims suggest the mixture is running rich.
  7. Clear the code, complete a drive cycle that mirrors the freeze frame conditions, and verify the check engine light remains off. If P0264 returns, the fault is confirmed and the circuit requires further component-level testing.

Repair Options and Costs

Corrective action depends entirely on which component is responsible for the low circuit condition:

  • Replace fuel rail pressure sensor or pressure regulator: $150–$450
  • Clean or replace fuel injectors: $200–$800
  • Replace fuel filter: $80–$200
  • Replace fuel pump assembly: $400–$900

Always begin with the least expensive possibilities — wiring repair, connector cleanup, or filter replacement — before committing to component replacement. Injector cleaning often resolves minor plugging at a fraction of replacement cost.

Total repair costs for P0264 typically fall between $80 and $900 depending on the underlying cause. An accurate diagnosis before purchasing parts prevents unnecessary expense — the fuel pump scenario represents the worst-case end of the range and is rarely the first item to blame.

Can You Drive With P0264?

Drive with caution. A cylinder that is not receiving proper fuel can cause stalling, hesitation, and unburned fuel entering the exhaust stream. Under severe conditions, raw fuel can overheat and damage catalytic converters. Limit driving to essential trips until the fault has been diagnosed and repaired.

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