The rocker arm oil pressure switch is a crucial component in an internal combustion engine’s lubrication system.
It serves the purpose of monitoring and regulating the oil pressure within the rocker arm assembly. By doing so, it ensures proper lubrication and functioning of the engine’s valvetrain.
If you experience P2646 code issues which is related to the rocker arm oil pressure switch, it’s essential to diagnose and resolve them promptly to prevent potential engine damage.
What Is Honda Rocker Arm Oil Pressure Switch?
The Honda Rocker Arm Oil Pressure Switch is a component in Honda vehicles that monitors the oil pressure in the rocker arm assembly.
The rocker arm assembly is responsible for actuating the intake and exhaust valves in an internal combustion engine. The switch is typically located near the cylinder head and is connected to the engine’s oil supply.
The purpose of the rocker arm oil pressure switch is to send a signal to the engine control unit (ECU) or the instrument panel to indicate the oil pressure status.
It helps the ECU determine if there is sufficient oil pressure for the proper functioning of the rocker arm assembly.
If the oil pressure drops below a certain threshold, the switch will trigger a warning light on the instrument panel or send a signal to the ECU to activate a warning.
By monitoring the oil pressure, the rocker arm oil pressure switch plays a crucial role in protecting the engine from damage.
Low oil pressure can lead to inadequate lubrication, which can cause excessive wear on engine components, including the rocker’s arms.
Additionally, low oil pressure may indicate a potential issue with the oil pump or oil circulation system, which should be addressed promptly to prevent engine damage.
If you suspect a problem with the rocker arm oil pressure switch, such as a faulty switch or low oil pressure reading, it is advisable to have it diagnosed and repaired by a qualified mechanic or authorized Honda service center.
They can accurately assess the issue and take the necessary steps to ensure the proper functioning of the engine’s lubrication system.
P2646 Honda: Rocker Arm Oil Pressure Switch – Low Voltage
Honda vehicles commonly display the diagnostic trouble code P2646. It indicates that the oil pressure switch for the rocker’s arm is malfunctioning.
Often referred to as the VTEC (Variable Valve Timing & Lift Electronic Control) switch, the Rocker arm oil pressure switch verifies oil pressure in the VVT mechanism.
It is most commonly caused by using the wrong weight oil during the last oil change if you get P2646.
You may wish to start by replacing the oil with Honda’s recommended oil if you’ve recently had an oil change.
What Is the P2646 Code?
The P2646 code is an OBD code that indicates that the “A” rocker arm actuator control circuit for bank 1 is not performing or is stuck off.
Variable valve timing and lift electronic control systems, such as those found in Hondas, increase fuel efficiency and engine performance.
Through the ECM, the VTEC system controls the rocker arm control system. Various timing and lift mechanisms in VTEC vehicles are powered by hydraulic pressure delivered by the rocker arm control solenoid.
ECM uses a rocker arm oil pressure switch to monitor and verify oil pressure, and the VTEC system adjusts valve timing and lift as needed. To ensure proper activation of the variable timing mechanism, this must be done.
ECMs set the P2646 code if the rocker arm oil pressure switch doesn’t receive the proper voltage signal.
In addition, the “A” in this code refers to the intake camshaft, and the bank 1 refers to the side of the engine with the number one cylinder.
What Are the Symptoms of a P2646 Code?
When you encounter the P2646 code, your dashboard’s Check Engine Light will illuminate, which is the first symptom you should expect.
It usually results in a decrease in engine performance because the engine valve is not moving or operating properly.
When one or more rockers are stuck in the wrong position, there will be a loud noise. Fuel consumption and engine performance can also be affected as a result.
What Are Some Causes of a P2646 Code?
A common cause of the P2646 code is when the ECM detects a problem with the bank 1 rocker arm system.
Low oil pressure and low oil pressure that does not meet manufacturer specifications are also indicators of low or dirty engine oil.
Rocker arm oil pressure sensors and faulty rocker arm oil control solenoids can also cause the code to be set. P2646 codes can also be caused by wiring issues.
In order to diagnose this problem, a qualified technician should inspect any potential wiring issues.
In addition, the code can also appear if the engine has excessive sludge binding the rockers or if the oil is too thick. The system will also cease to function properly if the oil viscosity is incorrect.
This would be a great place to start if you are unsure of the oil weight in your Honda or Acura. Check the dipstick even if you know the oil weight.
Ensure that it doesn’t appear milky. You might have some coolant leaking into the oil pan if the oil looks milky. In this case, the oil’s viscosity would be affected and the P2646 error would appear.
Bad VTEC/Rocker Oil Pressure Switch
Having checked the electrical connection and the oil, replacing the switch is the next step after checking the oil.
Most Honda vehicles have easy access to them. The cost of these isn’t that high either. This switch is covered in many technical service bulletins on Honda made vehicles.
P2646 indicates that the oil pressure switch for the VTEC/Rocker is not working correctly. It is very likely that a wiring issue is at fault.
Examine the wiring harness where it connects to this switch. Inspect it for damage and make sure the plug is securely connected. Make sure the wiring is not damaged anywhere along the way.
How Difficult Is It to Inspect a P2646 Code?
There are several steps to inspecting the P2646 code issue, and qualified technicians with previous experience should be entrusted with this task. If you attempt to repair your engine on your own, you could further damage it.
To inspect and repair the problem, a technician will replace the “A” rocker arm actuator and repair the wiring harness or connectors leading to it.
If necessary, the engine passages can be flushed of sludge and the oil and filter changed to correct the oil viscosity.
Can I Still Drive with a P2646 Code?
Driving for prolonged periods is not recommended by qualified technicians due to the potential failure of the variable valve timing system due to the P2646 code.
If you don’t do this, you risk further damage to your engine’s internal components and more expensive repairs.
The engine is strained and stressed when you operate your vehicle when it is not running efficiently, which can lead to serious damage.
It is recommended that you have your vehicle inspected at a certified service center as soon as possible by qualified technicians.
How Serious Is the P2646 Code?
Engine performance and power will be affected when the valve timing system is not working correctly, which is why the P2646 code is critical.
As well as causing fuel consumption to increase, this error code could cause severe damage to other engine internals. In order to prevent further engine damage, address the issue as soon as possible.
Honda recommends replacing one or both of the rocker arm oil pressure switches if the vehicle’s malfunction indicator lamp (MIL) is on and diagnostic trouble codes (DTC) P3400 (VPS Stuck Off Bank 1) and/or P3497 (VPS Stuck Off Bank 2) are present.
There may be intermittent failures of the oil pressure switch on the front and/or rear rocker arms. Verify that the wiring and connectors between the engine control module (ECM) and each switch and ground are correct. The switches are at fault if all test results are good.
How Much Does It Cost To Fix Code P2646?
P2646 can be fixed by just changing your oil, which is great news. You can find this solution for a very low price. You may also have to consider some expensive options.
The Bottom Line
It is possible to completely avoid the Honda P2646 trouble code in many cases. The engine won’t get sludge buildup with a normal oil change and the right viscosity.
If you follow the recommended maintenance schedule, you won’t need to worry about the P2646 DTC.
Only Honda vehicles display the P2646 code, so keep that in mind. Most vehicles do not have actuators for the rocker’s arms. This code will only be thrown by engines with variable rockers.