P0264

Cylinder 2 Injector Circuit Low

P0264 is a generic OBD-II powertrain diagnostic trouble code: Cylinder 2 Injector Circuit Low. It is logged by the engine control unit when the fuel/inj monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P0264
Group
Powertrain
System
Fuel/Inj
Severity
Warning (MIL on, possible limp mode)
Need P0264 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P0264 means

P0264 is stored when the ECM/PCM detects a lower-than-expected voltage in the fuel injector control circuit for cylinder 2. The code follows exactly the same electrical pattern as P0261 (cylinder 1 injector circuit low) but is attributed to the cylinder 2 injector driver channel. The ECM activates each injector by grounding its control circuit through an internal driver transistor; a low-circuit reading on cylinder 2 indicates the expected voltage drop is not occurring cleanly, implying a wiring open, a ground-side short, or a coil fault that prevents normal current flow.

When the cylinder 2 injector circuit is compromised, the injector may fire weakly or not at all. Cylinder 2 then delivers insufficient fuel, causing a misfire (P0302) and rough running. On vehicles where each injector is driven independently by the ECM — which is standard on all modern engines — the fault is isolated to cylinder 2 and does not directly affect other cylinders' injector operation.

Harness wiring between the ECM and the cylinder 2 injector is the most common failure point: vibration, heat cycling, and engine oil contamination cause connectors to corrode or wires to develop high-resistance opens over time. The injector coil itself is the second most common culprit. The ECM driver is rarely at fault and should only be suspected after the full circuit has been checked and verified.

Common causes

Most-frequently reported root causes when P0264 is logged.

  • 1
    Open circuit or high-resistance fault in the cylinder 2 injector wiring harness
  • 2
    Corroded, loose, or damaged electrical connector at the cylinder 2 fuel injector
  • 3
    Shorted or open-circuit injector solenoid coil on cylinder 2
  • 4
    Weak or missing ground return path for the cylinder 2 injector circuit
  • 5
    Blown injector fuse or failed injector relay interrupting power to the cylinder 2 injector
  • 6
    Fuel injector control module failure (on vehicles using a separate injector driver module)
  • 7
    Failed ECM/PCM driver transistor for the cylinder 2 injector channel (rare)

Symptoms drivers notice

Check engine light illuminated, frequently accompanied by P0302 (cylinder 2 misfire) code
Rough idle and noticeable vibration attributable to cylinder 2 misfiring
Reduced engine power, poor throttle response, and sluggish acceleration
Increased fuel consumption as the engine management compensates by enriching other cylinders
Possible stalling or difficulty restarting if the fault causes a severe enough misfire at idle
Black smoke or smell of unburnt fuel on some engines if adjacent cylinder fuelling is overcorrected

How to diagnose P0264

A typical diagnostic flow when this code is present.

  1. 1
    Connect a scan tool, retrieve all stored DTCs and freeze-frame data, and confirm whether P0302 and/or other injector circuit codes are present alongside P0264.
  2. 2
    Visually inspect the cylinder 2 injector connector and wiring harness for corrosion, bent pins, oil soaking, chafing, or heat damage.
  3. 3
    Disconnect the cylinder 2 injector connector and measure the coil resistance with a digital multimeter; compare the reading to manufacturer specification (commonly 12–16 Ω for high-impedance injectors).
  4. 4
    Perform a noid light test at the cylinder 2 injector connector to confirm the ECM is generating a drive signal on that channel.
  5. 5
    Check supply voltage at the injector power pin with the ignition on; low voltage here points to a fuse, relay, or supply-side wiring fault.
  6. 6
    Inspect the harness routing from the injector to the ECM for pinched, corroded, or broken wires; repair any damaged sections before suspecting the injector or ECM.
  7. 7
    Substitute a known-good injector from another cylinder if the circuit checks pass but the fault persists, to confirm whether the injector coil has an intermittent internal fault.

Related powertrain codes

Frequently asked questions

Is P0264 the same fault as P0261 just on a different cylinder?

Electrically yes — both are injector circuit-low faults, differing only in which cylinder's driver channel is affected. The diagnostic procedure is identical; only the physical location of the wiring, connector, and injector changes. If both P0261 and P0264 appear simultaneously, suspect a common power supply, shared fuse, or a wiring harness section that runs alongside both injectors.

Can I drive with P0264 to the workshop?

For a short distance, yes, but it is not advisable for extended driving. Cylinder 2 will misfire continuously, causing unburnt fuel to reach the catalytic converter, which can cause overheating and internal catalyst damage if the misfire persists. Reach the workshop promptly.

I replaced the cylinder 2 injector but P0264 came back. What else should I check?

If a new injector does not resolve the code, the fault is in the wiring or the ECM driver. Check connector pin tension, inspect the harness for a micro-fracture that only opens under engine vibration, and verify the injector ground path resistance from the ECM ground pin to chassis ground. A noid light test while wiggling the harness can reveal an intermittent break.

Does P0264 affect the other cylinders?

Not directly. Each injector is driven by a dedicated output channel in the ECM, so a fault on the cylinder 2 channel does not interrupt the other channels. However, the engine management system may apply fuel trim corrections to the remaining cylinders to compensate for the lost combustion contribution from cylinder 2, which can cause secondary codes or apparent lean/rich conditions.

Disabling P0264 in software

RaceTune can permanently disable P0264 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P0264 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file