P2646 Honda? (TOP 5 Tips)

  • P2646 is a common diagnostic trouble code that affects Honda made vehicles, including the Element. This code indicates that there is an issue with rocker arm oil pressure switch.

How do I fix error code P2646?

What repairs can fix the P2646 code?

  1. Replacing the ‘A’ rocker arm actuator.
  2. Repairing the wiring harness or connector to the actuator.
  3. Changing the oil and filter to the correct viscosity oil.
  4. Flush the engine passages of sludge from lack of oil changes.

What is code P2646 Honda?

Diagnostic Trouble Code (DTC) P2646 code stands for “ A” Rocker Arm Actuator System Performance/ Stuck Off (Bank 1).” It’s a generic OBD-II powertrain code supported by a variety of makes and models. VTEC is a variable valve timing system developed by Honda to improve your vehicle’s fuel efficiency.

How much does it cost to fix a rocker arm actuator?

Because rocker arm repair is tedious work, it can be time intensive so hiring an auto mechanic or dealership to do the job is not cheap. Expect to pay anywhere from $500 to $1,500 (parts + labor) depending on the vehicle.

What are the symptoms of a bad VTEC solenoid?

What are the symptoms of a bad VTEC solenoid? The most likely scenario with a VTEC solenoid failure is when you get a check engine light, and the car will likely go into limp mode, often leaving you fearing the worst.

How do I fix error code P2647?

What repairs can fix the P2647 code?

  1. Adding or changing the engine oil.
  2. Replacing the timing belt or chain as well as other timing components.
  3. Replacing the oil control valve or other variable valve timing components.
  4. Repairing or replacing wiring or connectors that are associated with the variable valve timing system.

What does a rocker arm oil control valve do?

The Oil Control Valve (OCV) is a a critical part used in every engine that is fitted with variable valve technology (VVT). A single control valve will regulate the supply of oil to a designated VVT hub, to advance or retard the timing by altering the camshaft angle position.

What does the rocker arm actuator do?

The rocker arm actuator is an oil pressure switch which controls the flow of oil to critical upper engine cylinder head components.

Can a bad rocker arm cause a misfire?

The most common symptom of a bad rocker arm is clicking or ticking noises coming from the cylinder head of the engine. It can also cause misfires or a stalling engine together with a check engine light on your dashboard.

How do I fix error code P2649?

What repairs can fix the P2649 code?

  1. Replacing the ‘A’ rocker arm actuator.
  2. Repairing the wiring harness or connector to the actuator.
  3. Following the manufacture pinpoint test to isolate faults in the system.

How do I bypass the VTEC oil pressure switch?

This can be easily bypassed with a simple wiring trick: On your engine harness, locate the VTEC oil pressure switch plug/wire (this wire comes from OBD1 ECU pin D6). Use a common T-tap or other method and simply tap this into the VTEC solenoid valve wire (the VTEC solenoid wire comes from OBD1 ECU pin A4).

How long can I drive with a bad rocker arm?

If your lifters are bad or collapsed, you shouldn’ t drive more than 100 miles and you should use those miles to drive your vehicle to the repair shop.

Is it hard to replace a rocker arm?

When you hear a rapid ticking sound coming from the engine, there is an issue with the rocker arms. More often than not, the ticking sound occurs because of low engine oil levels. It does not take very ling to replace a rocker arm and you can complete the project in your driveway.

How do I know if my rocker arm is bad?

Any kind of fault and damage to rocker arm will reduce the power of the engine and even it can cause complete failure of the engine. Common Symptoms of the Bad Rocker Arm:

  1. 1 Clicking or Ticking Noises:
  2. 2 Weak Engine Performance or Stalling:
  3. 3 Engine Light On:
  4. 4 Physical Deterioration:

Honda Accord P2646: Rocker Arm Oil Pressure Switch Circuit → Low Voltage

P2646 is an often encountered diagnostic problem code that affects automobiles manufactured by Honda, notably the Accord. This number indicates that there is a problem with the oil pressure switch on the rocker arm. The VTEC (Variable Valve TimingLift Electronic Control) switch, also known as the rocker arm oil pressure switch, is a device that checks the right oil pressure in the Variable Valve Timing (VVT) mechanism, and it is located on the rocker arm. It is possible that your Honda Accord is experiencing P2646, and the most typical causes for this is that the incorrect weight of oil was used at the most recent oil change, that the oil level was low, or that the oil was extremely unclean.

P2646 Symptoms:Honda Accord

When the P2646 error code appears on its own, it is not generally associated with any visible drivability problems. It is possible that you will notice a slight decrease in performance and fuel consumption. If the VTC strainer screen becomes clogged, the engine may shut down when subjected to prolonged high-speed acceleration. An example of a VTEC switch. Isn’t there a screen to your right? It has the potential to get filthy, resulting in P2646.

P2646 Causes:Honda Accord

The variable valve timing system in your Accord is controlled by the VTEC system. This is accomplished by the activation of the VTEC/Rocker arm solenoid. When it comes to monitoring the pressure of this system, it makes use of the Rocker Arm oil pressure switch. When the pressure is lower than the solenoid, the check engine light will on, and the code P2646 will be displayed on the dashboard. This excellent video by jimthecarguy on YouTube demonstrates how to diagnose P2646. The following are the most often seen causes of P2646:

  • If you are unclear about the oil weight that was used in your Accord’s most recent oil change, this would be a good place to start your investigation. Even if you are confident in the weight of the oil, you should check the dipstick. Make certain that it does not seem milky. If the coolant seems to be milky, it is possible that some of it is seeping into the oil pan. The majority of the time, this is caused by a leaky head gasket. This would reduce the viscosity of the oil and cause the P2646 to occur. When the dipstick does not register any oil at all, the oil level may be too low to allow the VTEC system to work correctly
  • Low Oil Electrical Problem– The P2646 code indicates that the voltage coming from the VTEC/Rocker oil pressure switch is inadequate. This implies that a wiring issue might very likely be at the root of the problem. Take a look at the wire harness that connects this switch to the power source. Check to see that it is not damaged and that it is properly plugged in. Trace the wire all the way down to its source to determine whether it has been damaged in any way. Bad VTEC/Rocker Oil Pressure Switch– After inspecting the oil and ensuring that it is in good condition, as well as verifying the electrical connection, the next step is to replace the switch. They are not difficult to access on the vast majority of Honda automobiles. Furthermore, they are not prohibitively expensive. There are a plethora of technical service bulletins available for Honda-built vehicles in preparation for this move
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Accord P2646 Conclusion

Good luck with your Honda Accord’s P2646 code diagnosis. If you have anything to contribute that you think might be useful to someone else who is working with this code, please leave a comment below with your thoughts. Thank you very much.

P2646 Honda

CR-V, Honda Element, and Honda Accord automobiles equipped with the 2.4L engine are seeing a high incidence of P2646 Honda problem codes, according to repair shops. The Honda code P2546 is defined as follows: P2646: Low Voltage in the VTEC Oil Pressure Switch Circuit. Honda has released a service bulletin13-021 to fix the issue on the cars mentioned below, which can be found here. Other issue codes, such as P2646 and P2651, may also be present in the car (rocker arm oil pressure switch circuit low voltage).

Models affected by P2646 Honda and service bulletin13-021

2003–12 Accord L42012–13 Civic ALL models, with the exception of the Si and Hybrid Civic (2002–05) Element2007–11 Si2002–09 CR-V2011 CR-Z2003–11 CR-Z2003–11 Fit2002–09

How to fix P2646 Honda trouble code

According to the service notice, the rocker arm pressure switch may experience occasional failures on a regular basis.

Honda has provided an upgraded component, part number 37250-PNE-G01, as well as part number 91319-PAA-A01, for the pressure switch.

How to test the VTEC oil switch

The VTEC oil switch is a usually closed switch in the traditional sense. Due to the fact that the blue/black wire is used for reference voltage and that when the switch is closed, it is grounded, the ECM expects to detect a significant voltage decrease when the switch is closed. The ground wire is a brownish-yellow in color. Check for good ground on the brown/yellow wire to get a solid start with your diagnostic. After that, while the engine is running, backprobe the connector to the oil switch and look for reference voltage on the blue/black wire on the blue/black wire.

How the VTEC oil switch works

When the engine’s RPMs hit the 2500-4000 range, the VTEC system is activated. At that point, the engine control module (ECM) initiates the VTEC solenoid, which opens and permits oil pressure to reach the intake valve rocker arms. In response to an increase in oil pressure, the oil pressure switch opens and prevents the reference voltage from falling below zero. As a result, the ECM sees the whole reference voltage rather than a significant voltage decrease.

What’s going on with the bad VTEC oil pressure switches

Because of the malfunctioning switches, they are moving into the open state at RPS 2500 and less, when they should be moving into the closed state.

Other causes forP2646 Honda

In the event that you’ve changed the VTEC oil pressure switch and are still seeing code P2646 at RPMs in the 2500-400 range, you may be experiencing a low oil pressure problem, filthy oil, a blocked VTEC screen, or a problem with the VTEC assembly. In that situation, make certain that the oil filter is fresh to guarantee that the pressure is not restricted or that the bypass mode is not activated. The year 2020 is a leap year. Rick Muscoplat is a professional musician. Rick Muscoplat posted a blog entry on

Diagnosing P2646 on 2005 Honda Odyssey Touring – ScannerDanner Forum

Mike355F1 submitted a 15:59:21:136 on May 31, 2018. I sent this to Mr. Danner, but he stated that here is the most suitable location for it. I’m not sure, I’m a newbie! Hello, Mr. Danner. I have a 2005 Honda Odyssey Touring that I’ve been attempting to diagnose and repair with no success. Due to the fact that I live in the Pittsburgh area, John Clark from Odyclub.com recommended you as the person to contact. He stated that you are in charge of diagnosing issues for a price. If this is right, could you please provide me with further information on how I can get anything set up?

  • The P2646 rocker arm actuator code has been appearing on my computer.
  • Although the solenoid passed the electrical test with flying colors, I am not sure whether it is mechanically functional due to the fact that I did not notice any movement of the pin within.
  • Dave101 published a blog post on May 31, 2018 at 17:3521138.
  • Check that the white/green wire is receiving electricity (+) before proceeding.
  • If I’m interpreting the schematic properly, the ground on this car flows from the PCM to the VTEC solenoid, which then feeds the ground to coils 1, 2, and 3 of the ignition system.
  • You presumably have better hearing than I do, so I’m going to guess that you don’t have both power and ground at the same time.
  • Because of this, I’m not sure if it’s a ground-side switch or not.

It is, however, something to set you off to a good start.

Mike355F1 posted a 13:00:21:149 on June 1, 2018.

I’m going to look into it and see what I discover.

If revving the engine will trigger VTEC or whether the engine must be under load is unknown.

Mike355F1 posted a new article on June 1, 2018 at 13:5021150.

Is it reasonable to assume that the green wire will only get electricity when it is under load or in the VTEC range?

bybruce.oliver on June 1, 2018 at 17:1521154 Have you checked the oil in your car?

Have you double-checked the oil pressure?

Bruce Oliver’s 01 June 2018 17:1721155 bybruce.oliver When this code is set, there is also a Technical Service Bulletin for a PCM reflash.

Dave101 published a blog post on June 1, 2018 at 18:31:157.

Is it reasonable to assume that the green wire will only get electricity when it is under load or in the VTEC range?

Here are a few examples of tests.

When you are driving the car under load, the battery voltage should be displayed on the decal.

When the solenoid is unplugged, the resistance should be around 20 ohms.

Please log in or create an account to participate in the discussion.

Using the video link, you can see that the pin inside is moving little (maybe 1/16 of an inch), and you can hear that it is doing something.

drive.google.com/file/d/0B2v.ew?usp=sharing Please log in or create an account in order to participate in the discussion.

Have you checked the oil in your car?

Have you double-checked the oil pressure?

Performing the Resistance Test on the solenoid is acceptable if the solenoid is a potential hazard.

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Bruce, I checked with Honda, and it appears that I have the most recent flash, at least according to them.

Thanks Please log in or create an account in order to participate in the discussion.

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Dave, What about the video I put shortly before your last post, which you may have missed?

Lastly, yes, I do have oil pressure, which is wonderful!

Dave101 published a post on June 1, 2018 at 18:54:1162 UTC.

Do you have any thoughts?

When I clicked on the link, Google informed me that the file did not exist.

If you receive a reading of 20 ohms or less, I would go to the next step.

You said that the solenoid may be bad mechanically; but, weren’t you the one who swapped it out with a known good?

Make certain that you are not just inspecting the signal line, but that it is also receiving a good ground.

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I had to replace the oil pressure switch on the VTEC.

Because I do not have access to a scanning tool, I am unable to execute the tests you specified.

I believe it is not mechanically operating correctly, but I cannot say for definite because I cannot find anything else to compare it against on the internet to confirm this.

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It is equipped with the first generation VCM (variable cylinder management), which regulates cylinder pause on the intake and exhaust valve side of the engine in the 2005 Odyssey.

(2nd generation VMC controls both the intake and exhaust valve sides of the heads).

In order to activate 3 Cylinder Pause mode, the Spool valve assembly, which comprises primarily of three components: the VTEC spool valve, the EOP (engine oil pressure sensor), and the VTEC solenoid valve, must be installed.

During NORMAL operating conditions*VTEC solenoid command ON- engine is operating in conventional 6 cylinder mode, the PCM anticipates the EOP sensor dropping to LOW (from previous experience, 6-8 psi is the criteria for LOW)*VTEC solenoid command OFF- engine is operating in conventional 6 cylinder mode, the PCM anticipates the EOP sensor remaining HIGH (above 6psi).

  1. I would want to point out that on a typical VTEC system that does not include a VCM, the logic conclusion is the inverse.
  2. The opposite is true when the command is turned off.
  3. I’d also use brake cleaner to clean the ports on the car.
  4. A VTEC solenoid valve in excellent operating order has an airtight seal and should not leak at any point during operation.
  5. If you have the ability, upload a video of it for others to see.
  6. byCurrentDraw.
  7. Mike355F1CurrentDraw, 03 Jun 2018 16:3621199byMike355F1CurrentDraw, Thank you for providing such a clear description of how the system performs and how the solenoid acts at each phase.

In the absence of electricity, I completely cleaned the pintle as you suggested, and no air seeps through.

Unfortunately, due to a scarcity of extra hands, I was unable to record footage with my phone during the event.

Dave101, I borrowed a multimeter and set it to the 200 Ohm scale on the basis of my findings.

What exactly does this imply?

I had believed that if I powered it up and it worked, it indicated that everything was well on the electronic front.

Thanks Please log in or create an account in order to participate in the discussion.

In general, most meters (Fluke, Snap-on, etc.) will display OL; however, ‘1’ shown on an ohmmeter almost certainly indicates that the resistance is greater than the ohm setting on the meter.

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The meter may have been defective or I may have used it improperly the first time, but below is a video of what I am seeing right now.

I was under the impression that when the leads were contacted, the voltage should be zero, but mine is 4.9, and when I touch the solenoid terminals, the voltage is 5.9. Please log in or create an account in order to participate in the discussion.

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Dreaded VTEC P2646 code – Tried everything

My 2005 Element (with 212K miles) was just infected with the P2646 VTEC malfunction code, which I discovered last week. When the CEL illuminates, the vehicle enters limp mode (the engine will not rev over 2800 RPM). When you turn the ignition off and back on, the car will come out of limp mode, but it will normally come back on soon after. My 2003 Honda CR-V (199K miles) has been experiencing the same problem for months – it displays as P1259 on the dash (VTEC malfunction) What I have done so far with the Element is as follows: 5W-20 oil and filter were replaced.

  1. The new VTEC oil pressure switch has been installed.
  2. On the block, the VTEC screen and gasket behind the P/S pump were replaced.
  3. According to all of the internet blogs and forums that I have explored, these remedies appear to be effective in resolving the bulk of the issues.
  4. On the 2003 CR-V, I went above and above, installing all of the aforementioned, as well as the following: The complete VTEC spool valve assembly was replaced (including another pressure switch) A 5-minute oil system flush was added to the oil to completely clean the system.
  5. Regular oil pressure sending unit has been replaced.
  6. Although I’ve never heard of anyone complaining about the long oil control valve in front of the block being faulty, I may try cleaning the screens on it next.
  7. Have you heard any recommendations about putting Marvel Mystery Oil in your oil?
  8. Never heard of anyone having success with it when they take it to a dealer.
  9. Any and all recommendations are welcome; I will continue to update this thread with what I have accomplished until they are up and working properly.

P1259 & P2646 codes – Tried everything!

VTEC system codes on 2.4-liter engines have been driving me insane. 2003 Honda CR-V with 199,500 kilometers. It started displaying the P1259 error number immediately after I purchased it. They will most likely come on in the first few miles of driving and may come on at odd intervals throughout the journey. RPM is restricted to 2800. If I turn off the ignition and immediately put it back on, the rev limitation is cleared and I can drive normally for a time. The following fixes have been attempted one at a time, with no discernible difference after each attempt.

  • Filter and gasket for VTEC solenoid, filter gasket for front of block, and screens for long valve at end of block were all replaced or cleaned.
  • The complete VTEC solenoid assembly, as well as another oil pressure switch, was replaced.
  • I added a motor flush to the oil and allowed it to sit for 5 minutes as instructed.
  • Oil pressure sending unit underneath the VTEC solenoid has been replaced.
  • I removed the valve cover and saw that there was no sludge accumulation – everything was clean.
  • VTEC solenoid appears to be experiencing a similar problem.

I tried swapping out the VTEC assembly with the original one that I removed from the CRV, but it had no impact. Any advice on where to go next would be greatly appreciated. I’ve tried every one of the ‘solutions’ that I could find on the internet.

P2646 Code

A similar ‘Blue Tooth’ gadget, dubbed ‘Fixd,’ was recently utilized on my 06′ RTL Ridgeline, and it produced the following code: ‘P2646’ Rocker Arm Oil Pressure Switch Circuit Low Voltage ‘ P2646’ Rocker Arm Oil Pressure Switch Circuit Low Voltage ‘ During the day of February 3rd, 2018, it was able to collect the following diagnostic information: 32.9 percent of the calculated engine load Engine coolant temperature: 177.8 degrees Fahrenheit fuel trimming on a short-term basis (Bank 1:9.38 percent) long-term fuel trimming (Bank 1:1.56 percent) short-term fuel trimming (Bank 2:5.47 percent) Bank 2:0.0 percent for long-term fuel trimming Absolute pressure in the intake manifold: 33 kPa RPM of the engine: 4638.0 rpm Vehicle speed: 52.79 miles per hour 35.0 degrees in ahead of the current time The temperature of the intake air is 60.8 degrees Fahrenheit.

  • Position of the throttle: 26.3 percent 20 percent of the throttle is applied relative to the location of the throttle.
  • Certain engines may create greater power at higher RPMs by varying the amount of time the valves are open.
  • Depending on how well the actuators that regulate these rocker arms are working, the engine may not produce as much power as it might or it may perform badly overall.’ I’m not sure what to do at this stage (I’m not a mechanic; I work in information technology).
  • I’m not precisely sure what further has to be done other than doing an Oil Pressure Switch Test at this time, despite the fact that the information Skelley521provided above appears to be straightforward.
  • It was on February 15th, 2018 that I replaced the OilFilter (the mileage at the time was 181,961), and I used the suggested 5W-30 oil (Mobil 1 High Mileage).
  • Q: I’m curious as to how much harm I’m doing to the Ridgeline by not having this professionally looked at.
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Low Oil and Vtec Solenoid Issues p2646

At no point did I notice a low oil level warning light come on. There isn’t any light like it. The sole ‘idiot light’ in the oil industry is the red ‘Too Late’ signal. It has the appearance of a gravy boat. Whether or whether I still had enough oil circulation in the engine to avoid causing major damage was a question. Is the engine making weird banging noises, as if it were being attacked by a Gremlin using a sledgehammer? If the answer is no, it is safe to believe there is no harm (ask a pro give it a listen).

If your oil level dropped to that low, it’s possible that you previously have a consumption problem or issue (or maybe a leak?).

Although not ideal, it is tolerable.

That is all your fault.) It is necessary to check the oil level at each gas station and to replenish the oil when necessary (stated in any owners manual) It is reasonable to anticipate even more consumption now that the oil has been let to run down to virtually empty levels.

Many elements inside rely on oil splash to provide lubrication, and extremely low amounts of oil remove a significant amount of it. HTH

P2646 – “A” Rocker Arm Actuator System Performance or Stuck Off (Bank 1) – TroubleCodes.net

Trouble Code Fault Location Probable Cause
P2646 Rocker arm actuator A, bank 1 – performance problem or actuator stuck off Wiring, rocker arm actuator

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What Does Code P2646 Mean?

A series of valves opens and shuts in response to the position of the piston in order to let air into and out of the cylinder as needed. The crankshaft drives the camshafts by the use of a timing belt or timing chain, depending on the engine. With each revolution of the crankshaft, rocker arms are pressed down on valves, which opens them to allow intake or exhaust into the cylinder. The appropriate valve timing (in respect to cylinder position) and lift vary depending on the engine speed and load conditions.

  • Because the technology to adjust valve timing or lift had not yet been developed, most engines were built with average cycle characteristics or with features that favored high or low end operating.
  • Because of the development of engines that have the ability to alter valve timing or lift, or both, the engine control unit will be able to adjust cycle characteristics based on engine operating circumstances and driver requirements.
  • As a consequence, greater power was available when it was needed, such as during acceleration, and better fuel efficiency was achieved while cruising.
  • Whenever the ECM senses that the system isn’t functioning properly, it will set a DTC (diagnostic problem code) and activate the MIL (memory indication light) (malfunction indicator lamp).
  • This term is used by Honda, Acura, and a few other automobile manufacturers.

What are the common causes of code P2646?

DTC P2646 can be caused by a variety of factors depending on the year, make, and model of the vehicle. Here are a few of the most often encountered.

  • VTEC system difficulties can be caused by a variety of factors, including a low oil level, wrong oil viscosity, and thinner oil. Low oil pressure conditions in particular sections of the engine, as a result of oil sludge, might prohibit the VTEC system from operating effectively.

What are the symptoms of code P2646?

If the variable valve timing system (VVT) is not functioning properly, you will most likely notice decreased engine performance and higher fuel consumption.

How do you troubleshoot code P2646?

  • Performing an oil check is essential to the proper operation of the VTEC system.
  • Check the level of the oil. The VTEC system will not be able to function properly if there is insufficient oil in the system to generate sufficient oil pressure. Make any required corrections.

Check to see that you’re using the proper oil for your engine.

  • Inspect your engine to make sure you’re using the proper oil for the job.

Oil sludge can interfere with the flow of oil into vital regions.

  • Electrical connections should be checked for corrosion, broken or bent pins, and that they are properly seated before use. Examine the wire harnesses for signs of evident damage. Whenever necessary, repair

Additional inspections may be impossible to do without the use of specialized equipment. For instance, using the scan tool to activate VTEC and checking oil pressure at the oil pressure switch might be a good idea.

Codes Related to P2646

  • The following codes are assigned to Bank 1: P2645’A’ Rocker Arm Actuator Control Circuit/Open (Bank 1)
  • P2647’A’ Rocker Arm Actuator System Stuck On (Bank 1)
  • P2648’A’ Rocker Arm Actuator Control Circuit Low (Bank 1)
  • P2649’A’ Rocker Arm Actuator Control Circuit High (Bank 1)
  • P2650’B’ Rocker Arm Actuator Control Circuit/Open (Bank 1)
  • P2651’B’ Rock

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