What Does It Mean?
This is a generic powertrain diagnostic trouble code (DTC) and generally applies to OBD-II vehicles. Vehicle makes may include, but are not limited to, Saturn, Land Rover, Porsche, Vauxhall, Dodge, Chrysler, Mazda, Mitsubishi, Chevy, Honda, Acura, Isuzu, Ford, etc.
The ECM (Engine Control Module) is responsible for monitoring, controlling, and adjusting many sensors and systems involved in your vehicle’s operation, not to mention detecting faults within said systems and circuits. One of the systems your ECM is responsible for monitoring and correlating with desired values is the intake manifold tuning valve.
I’ve heard many names for this component, but a “flapper” valve often comes up in the repair world. The intake manifold tuning valve has several possible purposes to aid your engine’s performance and operation. One is to regulate pressures between the intake plenums. Another can be to redirect intake air to a separate set of intake runners (or a combination) to change your engine’s airflow and potentially its performance. From my experience, the valve itself is mostly made of plastic, so you can imagine possible malfunctions combined with notoriously high temperatures in the engine compartment.
P065F is the fault code identified as “Intake Manifold Tuning Valve Performance, Bank 2” and it is a performance fault that has been identified by the ECM on bank #2. Bank #2 is the side of the engine that does not contain cylinder #1.
This code can be triggered by a mechanical or electrical fault with the intake manifold tuning valve. If you are in an area prone to extreme cold, it can cause the valve to malfunction and not turn properly according to the ECM’s commands.
A GM Intake Manifold Tuning Valve:
P065F Intake Manifold Tuning Valve
How Severe Is This DTC?
Depending on the actual issue related to your case, it can range from nothing to worry about to something quite serious and potentially damaging to your engine’s internal components. It would be a good idea to err on the side of caution when dealing with mechanical parts like the intake manifold tuning valve. The possibility of unwanted parts entering the engine’s combustion chamber is there, so keep that in mind if you are considering postponing this to another day.
What Are Some of the Symptoms of the Code?
Symptoms of a P065F diagnostic trouble code may include:
Poor engine performance
Rattling noise from the engine compartment
Reduced fuel economy
Possible misfires on startup
Reduced engine power
Altered power band
Cold start issues
What Are Some of the Common Causes of the Code?
Causes
of this P065F engine code may include:
Faulty intake manifold tuning valve (runner)
Broken valve parts
Stuck valve
Extreme cold
Wiring issue (e.g., chafed, cracked, corroded, etc.)
Damaged electrical connector
ECM problem
Valve contamination
What Are the Diagnostic and Troubleshooting Steps for P065F?
The first step in the troubleshooting process for any malfunction is to check the Technical Service Bulletins (TSBs) for known issues with the specific vehicle.
Advanced diagnostic steps become very vehicle-specific and may require the appropriate advanced equipment and knowledge to perform accurately. We include the basic steps below but refer to a repair guide specific to the year/make/model/powertrain for steps specific to your vehicle.
Basic Step #1
Whenever a DTC (Diagnostic Trouble Code) is triggered by the ECM, as a DIYer, it’s a good idea to clear all codes to see if it returns immediately. If not, take the vehicle on long and numerous test drives to see if it becomes active again after a few drive cycles. If it reactivates, proceed with diagnosing the active code(s).
Basic Step #2
First, you will need to locate the intake manifold tuning valve. This can be tricky as most often they are mounted inside the intake manifold itself. That said, the valve’s connector should be fairly accessible, so visually inspect it, look for broken tabs, melted plastic, etc., to ensure it is making a proper electrical connection.
Basic Step #3
Depending on the capabilities of your OBD2 code reader/scan tool, you may be able to operate the valve electronically with it. If you find this option, it can be a good way to determine if the valve is operating through its full range. Additionally, if you are experiencing rattling noises from your intake, this would be a good way to determine if the intake manifold tuning valve is responsible. If you hear an abnormal rattling from the intake while you are adjusting the sensor with your scanner, chances are there is an obstruction or the valve itself is stuck for some reason.
At this point, it would be a good idea to remove the valve and physically inspect it and the inside of the intake manifold for obstructions. If there are no obstructions and the rattling is present, you can try replacing the valve; it’s likely the issue. Keep in mind that, in some cases, this is not an easy task, so do your research beforehand to avoid ending up without the right parts, tools, etc.
NOTE: Always consult the manufacturer’s technical data before performing any repairs or diagnostics on your vehicle.
Basic Step #4
Make sure not to forget to inspect the wiring harness involved with the tuning valve. These wiring harnesses can be routed through engine parts and other high-heat areas, not to mention potential chafing/cracking related to engine vibrations.
Basic Step #5
If you have tried everything, take a look at your ECM (Engine Control Module), especially if multiple unrelated codes are currently active or activating and deactivating intermittently.
This article is strictly for informational purposes only, and the technical data and service bulletins for your specific vehicle should always take precedence.