Technical Description of OBD-II Trouble Code
High Control Circuit for Intake Manifold Tuning Valve in Bank 2
What does that signify?
This is a generic diagnostic trouble code (DTC) for powertrain and is commonly found in OBD-II vehicles. It can be applicable to various vehicle makes such as Saturn, Land Rover, Porsche, Vauxhall, Dodge, Chrysler, Mazda, Mitsubishi, Chevy, Honda, Acura, Isuzu, Ford, etc.
The Engine Control Module (ECM) is responsible for monitoring and adjusting multiple sensors and systems involved in the operation of your vehicle. It also detects faults within these systems and circuits. One of the systems that the ECM monitors and correlates with desired values is the Intake Manifold Tuning Valve.
This valve is often referred to as a “flapper” valve in the repair world. It serves multiple purposes to enhance your engine’s performance and drivability. One purpose is to regulate pressures between intake plenums. Another purpose may be to redirect intake air to a separate set of intake runners, thereby altering the flow and potentially improving the engine’s performance. The valve is primarily made of plastic, which can lead to malfunctions due to the high temperatures in the engine compartment.
P0665 is the trouble code identified as “Intake Manifold Tuning Valve Control Circuit High Bank 2,” indicating that the ECM has detected an excessively high electrical reading from the valve on bank #2. Bank #2 refers to the side of the engine that does not contain cylinder #1.
This code can be triggered by either a mechanical or electrical fault with the intake manifold tuning valve. In areas with extreme cold weather, the valve may malfunction and fail to rotate smoothly according to the ECM’s instructions.
A GM intake manifold tuning valve:
What is the severity of this DTC?
Depending on the specific problem in your case, the severity can range from nothing to worry about to something quite severe and potentially damaging to your engine’s internals. It is advisable to err on the side of caution when dealing with mechanical parts like the intake manifold tuning valve. There is a possibility of unwanted parts entering the engine’s combustion chamber, so it is important to keep this in mind and not postpone addressing the issue.
What are some of the symptoms of the code?
Symptoms associated with a P0665 diagnostic code may include:
What are some of the common causes of the code?
Possible causes for this P0665 engine code may include:
What are some P0665 diagnostic and troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB) for known issues with your specific vehicle.
Advanced diagnostic steps may vary depending on the vehicle and may require specialized equipment and knowledge for accurate diagnosis. The following are basic steps, but it is recommended to refer to a vehicle-specific repair guide for detailed steps pertaining to your vehicle’s year, make, model, and powertrain.
Basic Step #1
As a DIYer, it is a good idea to clear all codes when the ECM activates a DTC. If the code does not immediately reappear, take the vehicle for long test drives to see if the code becomes active again after a few duty cycles. If it does reactivate, proceed with diagnosing the active code(s).
Basic Step #2
Locate the intake manifold tuning valve, which may be challenging as it is often mounted internally within the intake manifold itself. However, the valve’s connector should be easily accessible, so visually inspect it for any broken tabs or melted plastic that may affect its electrical connection.
Basic Step #3
If your OBD2 code reader/scan tool allows it, try operating the valve electronically using the tool. This can help determine if the valve is functioning within its full range. Additionally, if you hear abnormal clicking noises from the intake while adjusting the sensor with your scanner, there may be an obstruction or a stuck valve causing the issue.
At this point, it is advisable to remove the valve and physically inspect it, as well as the inside of the intake manifold, for any obstructions. If no obstructions are found and the clicking noise persists, replacing the valve is likely the solution. However, keep in mind that this task may not be easy, so it is important to conduct thorough research beforehand to ensure you have the necessary parts and tools.
NOTE: Always refer to the manufacturer’s technical data before performing any repairs or diagnostics on your vehicle.
Basic Step #4
Do not forget to inspect the wiring harness associated with the tuning valve. These harnesses can be routed through engine parts and other high-heat areas, which may lead to chafing or cracking due to engine vibrations.
Basic Step #5
If all else fails, examine your ECM (Engine Control Module), especially if multiple unrelated codes are currently active or intermittently appearing and disappearing.
This article is intended for informational purposes only, and it is always recommended to prioritize the technical data and service bulletins provided by the manufacturer for your specific vehicle.
