Technical Description of OBD-II Trouble Code
Low 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 or a combination of runners, thereby altering the flow and potentially the performance of your engine. The valve is primarily made of plastic, which can lead to malfunctions due to the high temperatures in the engine compartment.
P0664 is the trouble code identified as “Intake Manifold Tuning Valve Control Circuit Low Bank 2,” indicating that the ECM has detected an electrical reading that is too low 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 not 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 fairly severe that could potentially damage 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 keep that in mind if you were considering delaying the repair.
What are some of the symptoms of the code?
Symptoms of a P0664 diagnostic code may include:
What are some of the common causes of the code?
Possible causes for this P0664 engine code may include:
What are some P0664 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 are highly vehicle-specific and may require specialized equipment and knowledge for accurate performance. The basic steps provided below should be supplemented with a vehicle year/make/model/powertrain specific repair guide for precise instructions.
Basic Step #1
As a DIYer, it is a good idea to clear all the codes when an ECM-activated DTC (Diagnostic Trouble Code) is detected to see if it reappears immediately. If it does not, take the vehicle for long and numerous test drives to check if the code becomes active again after a few duty cycles. If it reactivates, proceed with diagnosing the active code(s).
Basic Step #2
First, locate the intake manifold tuning valve. This may be challenging as it is often mounted internally within the intake manifold itself. However, the valve’s connector should be fairly accessible, so visually inspect it for any broken tabs, melted plastic, etc., to ensure it is making a proper electrical connection.
Basic Step #3
If your OBD2 code reader/scan tool allows it, you may be able to electronically operate the valve 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 is a possibility of an obstruction or a stuck valve.
At this point, it would be 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 conduct thorough research beforehand to ensure you have the necessary parts and tools to avoid being stranded.
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 other steps have been attempted without success, examine your ECM (Engine Control Module), especially if multiple unrelated codes are currently active or intermittently appearing and disappearing.
This article is solely for informational purposes, and the technical data and service bulletins specific to your vehicle should always take precedence.
