OBD-II trouble code
P0065: Air Assisted Injector Control Range/Performance
SAE J2012: air assisted injector control range/performance. The module commanded the function and the response was outside the test. Confirm this engine has the hardware. A blocked passage is one thing to inspect. It is not a ranked cause on this page.
Quick facts
- System
- Powertrain
- Category
- Fuel Injectors
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $125 – $183 (check engine light diagnosis, labor only; air-assist injector valve replacement not priced)
- DIY difficulty
- Intermediate DIY
Browse every code in P0001–P0099, or start from the full code library.
What does P0065 mean?
SAE J2012 APR2002 names P0065 Air Assisted Injector Control Range/Performance. P0066 is the circuit or circuit-low code and P0067 is circuit high. Range/performance means the commanded effect did not match the test. It is not, by itself, a statement that a wire is open.
Air-assisted injection is not on every engine. The service information has to show the valve, the hoses, and where the assist air is taken before any of this procedure applies. Some layouts use a solenoid and hoses. Some route air in a casting. Do not order "the air assist valve" until the parts diagram shows one.
YourMechanic's P0065 procedure (Andrew Quinn) starts by checking the lines for restriction, then the valve, then the wiring. Restriction in a line or a passage is on that list. This page does not rank it above the valve or the circuit, and it does not call carbon the cause by a margin. Where the air is taken from, and whether the airflow sensor has already measured it, is in this engine's diagram. Do not call the air unmetered unless that diagram says the pickup is upstream of the meter.
The monitor runs only inside the enable this procedure prints. YourMechanic's P0065 article does not state a cold, light-load idle window. Read the soak and the load on this chart before you try to reproduce the code.
Command the valve with a scan tool. Do not feed the solenoid from the battery to "see if it clicks" unless this procedure says that is the test and names the terminals. Applying battery voltage to the wrong pin can damage a driver.
The engine can be driven. What changes, if anything, is cold running. There is no universal idle or emissions number on this page.
Common causes
- This engine has no air-assist hardware, and the code was chased from the generic title
- A restricted hose or passage, found by inspecting the lines this diagram shows
- A valve that is commanded and does not change airflow or idle the way this test requires
- A cracked, collapsed, or disconnected assist hose
- An intake leak that hides the airflow change the monitor is looking for
- P0066 or P0067 stored as well, which are the circuit tests and come before a passage cleaning
- A calibration mismatch after a module replacement, confirmed in service information for this engine
Symptoms
- Check engine light with P0065
- The monitor will not run on a hot engine when the enable requires a cold soak
- P0066 or P0067 stored with it
- A rough idle only while cold, if this engine uses the assist for cold running
- No complaint once the engine is warm
- No air-assist parts on the engine, which stops the generic diagnosis
Diagnostic steps
- 1.Confirm the parts diagram shows an air-assist system on this engine. If it does not, stop and read the code with equipment that shows the manufacturer's description.
- 2.Read the enable. If it requires a cold soak and a light load, do not try to reproduce the code on a hot engine.
- 3.Read the freeze frame for coolant temperature and load so the road test matches the trip that set the code.
- 4.Inspect the hoses the diagram shows for cracks, collapse, and disconnection before any electrical test.
- 5.Check the passages or screens the procedure names for restriction. YourMechanic's write-up starts with the lines. Cleaning is the repair only when a restriction is actually there.
- 6.Command the function with a scan tool at the idle the enable allows and watch the airflow or idle-speed change this test specifies. No universal rpm change is stated here.
- 7.If P0066 or P0067 is stored, test that circuit before you condemn a passage. Verify the valve is being commanded before you call the driver failed.
- 8.Rule out an intake leak that would hide the small airflow change, using the smoke or propane method this procedure allows, away from hot exhaust and ignition.
- 9.After the repair, repeat a start from the soak the enable requires and confirm the monitor runs.
Repair cost
$125 – $183 (check engine light diagnosis, labor only; air-assist injector valve replacement not priced)
P0065: No RepairPal parts-and-labor price for an air-assist valve was found. The printed pair is RepairPal check-engine-light diagnosis only, updated 3 September 2026, $125–$183, labor only. A valve, a hose, passage cleaning, and an injector are outside it and need a quote for this engine. RepairPal's $317–$409 fuel-pressure-regulator job is a rail or line regulator after depressurizing. It is not this valve and is not included in the pair. RepairPal's air-injection control valve average, $613–$767, is the secondary-air valve between the air pump and the exhaust. That is not an air-assisted injector valve, so it is not used here. YourMechanic lists a P0065 check-engine diagnostic at $154.99, with $50 credited toward the repair. That is diagnosis, not the valve. RepairPal's air-injection control solenoid average, $144–$175 on 3 September 2026, is mounted at the air pump or on the valve between the pump and the exhaust manifold. That is secondary air, not an air-assisted injector valve, so it is not used here. No parts-plus-labor total for the air-assisted injector valve was found.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with air-assisted injection system service preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.