P0264 on the 6.0L Power Stroke is a cylinder 2 injector circuit low fault. The 6.0L fires its HEUI injectors electrically through the fuel injection control module (FICM), which sends high-voltage pulses through the valve cover harness to each solenoid. P0264 means the FICM detected the cylinder 2 injector control circuit reading low, indicating a short to ground, an open, or a solenoid that is not drawing current properly on that cylinder.
Single-cylinder injector codes are common on the 6.0L because injector power runs through connectors and a harness under the valve cover, where oil and heat break down insulation and corrode pins. P0264 points you straight to the cylinder 2 circuit, so you can focus your inspection. In most cases the fix is a wiring or connector repair rather than a new injector, provided you verify the electrical path first.
What P0264 means
The FICM drives each injector solenoid and watches the circuit. P0264 sets when the cylinder 2 control circuit reads low, which typically means a short to ground, an open, or a solenoid that is not responding. It is an electrical code that points to the cylinder 2 wiring, the under-valve-cover connector, or the solenoid rather than to injector fuel metering wear.
Common causes
- Damaged valve cover harness or corroded connector on cylinder 2
- Injector wiring shorted to ground or chafed
- Failed cylinder 2 injector solenoid
- Low FICM operating voltage
- Oil intrusion in the under-valve-cover connector
Symptoms
- Misfire or rough idle on cylinder 2
- Reduced power and hesitation
- Hard hot starting
- Check engine light with P0264 stored
- Smoke from unburned fuel
How to diagnose it
Check FICM operating voltage with a scan tool, since weak FICM output can trigger injector circuit faults. Run an injector buzz test and note whether cylinder 2 responds; silence on that cylinder points to the circuit or solenoid. Inspect the valve cover harness and the under-valve-cover connector for oil, corrosion, and cracked insulation. Measure the cylinder 2 solenoid resistance and check the wiring from the FICM for a short to ground or an open.
How to fix it
Repair chafed or shorted wiring and clean or replace a corroded under-valve-cover connector first. Correct low FICM voltage by repairing power and grounds or replacing the FICM if its output is weak. If the wiring and FICM are good but cylinder 2 fails testing, replace that injector. After the repair, clear the code, confirm cylinder 2 responds in a buzz test, and road test. For harnesses, connectors, FICMs, and injectors for your 6.0L, contact sales@coredieselparts.com.
Frequently asked questions
Is P0264 a wiring or an injector problem?
It is an electrical circuit code, so start with the valve cover harness, the connector, and FICM voltage. Only replace the cylinder 2 injector after confirming the wiring and solenoid.
Why does cylinder 2 keep setting codes?
Oil and heat under the valve cover degrade the connector and harness. Repeated single-cylinder codes usually trace to that connector rather than to repeated injector failures.
Can P0264 cause hard starting?
Yes. A weak or dead cylinder makes cold and hot starts harder and produces rough running until the circuit is repaired.
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