OBD-II code family
Air Assisted Injector Control Faults (3 codes)
3 related fault descriptions. Use each full code and the exact vehicle service information to identify its circuit, monitored condition, and required tests.
Codes in this family
This is the complete published member list for this guide. Each code retains its own page; shared diagnostic context does not mean that every member has the same test or repair.
What these codes mean
P0065 identifies air-assisted injector control range/performance. P0066 retains the circuit or circuit-low description, while P0067 identifies circuit high. The member list preserves those different conditions; none selects a replacement injector, valve or controller by itself.
Identify the engine, full manufacturer DTC and installed air-assist system before testing. The generic label does not establish an external solenoid, separate air hose or particular connector. Air-control hardware and the method used to evaluate it must come from the actual system information.
Range/performance requires the expected command and response to be established. It does not prove normal wiring or distinguish a restricted path from a component that fails to respond. Low/high identifies the classified circuit result, not a universal short-to-ground, open-winding or lost-supply diagnosis.
Preserve the scan and event conditions. Inspect accessible cooled connections using the correct diagram, then have the specified supply, return, control and functional checks performed. Do not bridge terminals or apply battery voltage to unidentified components. A click, static resistance or one successful command is not a complete function check.
Obtain an itemized quote once testing identifies the fault. A diagnostic-service example does not price a replacement or prove which component is serviceable. Base driving decisions on actual symptoms and warnings rather than assuming this code guarantees normal engine operation.
Identify the circuit on your vehicle
Match the full DTC, reporting module, and any failure-type suffix to the service information for your exact year, make, model, engine, and equipment. An identifier alone does not establish installed hardware count, location, connector pinout, or a universal measurement.
Where the manufacturer publishes its own meaning for this code, that is the one to work from — it describes the actual component on your vehicle, which the generic definition cannot. Keep the generic description for what it is good for: it tells you which subject area the standard assigned the code to, which is useful context when the two appear to disagree. If they do disagree, follow the manufacturer.