[Rashinal]

I agree. I have replaced the VTEC solenoid and had all other sensors checked by a dealership. Once I went to conventional oil, it seems to run a lot longer between "Limp-mode" occurrences. I can only think that it is eother the ECU/PCM or something else electrical. The oil pan was clean, upper-motor was clean... runs strong out of "Limp Mode"... just don't know what else to check as I have had 5 different mechanics look at it and test the electrical harness going to the switch, etc... Ghost in the machine!

 

[patrickjamesyu]

I agree. I have replaced the VTEC solenoid and had all other sensors checked by a dealership. Once I went to conventional oil, it seems to run a lot longer between "Limp-mode" occurrences. I can only think that it is eother the ECU/PCM or something else electrical. The oil pan was clean, upper-motor was clean... runs strong out of "Limp Mode"... just don't know what else to check as I have had 5 different mechanics look at it and test the electrical harness going to the switch, etc... Ghost in the machine!

Have you had your oil pressure checked?


Sent from my iPhone using Tapatalk

 

[butterblum]

FWIW, I had this code this weekend. I pulled off the solenoid assembly to check the strainer, which was totally clean. I put it back on and made sure the wires were firmly seated in the connectors. I then went for a drive and haven't had a problem since.
I did a valve adjustment two weeks ago, so my best guess is that I put too much tension on the oil pressure sensor wires, and for some reason, it took 2 weeks for the problem to manifest itself.
Check the connections before anything else.

This problem reoccurred again this week; so about 2,000 miles later. It happened after a particularly rainy drive through rural Ohio. I tried re-seating the electrical connections to no avail. I kept it under 50mph on the way home and had the issue all the way home. At some point after I got home, it just went away again. I then proceeded to clean the connections with contact cleaner and try and waterproof it with some dielectric grease. I haven't had an issue in the 100 miles since, but I am really confused as to what wight be causing this.

 

[butterblum]

This problem reoccurred again this week; so about 2,000 miles later. It happened after a particularly rainy drive through rural Ohio. I tried re-seating the electrical connections to no avail. I kept it under 50mph on the way home and had the issue all the way home. At some point after I got home, it just went away again. I then proceeded to clean the connections with contact cleaner and try and waterproof it with some dielectric grease. I haven't had an issue in the 100 miles since, but I am really confused as to what wight be causing this.

I had this pop up again. I bit the bullet and spent the $160 on the solenoid and pressure sensor assembly this time.
After a loop around the block with the new assembly, my CEL cleared itself.
My theory is that my solenoid was stuck in the on position. See attached.

 

[Rashinal]

Yes, by a dealership. It drops pressure randomly and they were left stumped.

 

[Rashinal]

Have you had your oil pressure checked?

Yes, by the Honda dealership. they said it just randomly drops in pressure at highway speeds. No consistency and they said "I don't know what the problem is".

 

[Watt-man]

Good thread. One thing that many don't pick up on is that there are two things going on with our i-VTEC system: ONE is the classic "VTEC" rocker arm locking to change valve lift and duration, the OTHER is phasing of the intake camshaft. This is probably trivia, but I haven't seen one thing answered in this thread:

Which assembly is controlling rocker arm locking and which is controlling intake cam phasing? I was thinking item 7 in the diagram below was rocker arm locking and item 4 in the diagram below was phasing. Now I think it's the opposite.

Which is it?

edited to add: i realize the phasing is completed by the sprocket on the end of the intake cam, but I'm assuming the oil pressure that it receives to control phasing is supplied by #7 or #4.

 

[tonymeans]

Hey I had same problem.....there are actually two oil screens that have to be cleaned....there is the solenoid screen and a screen on the front of the engine block below the tensioner....this gets blocked which lowers the oil pressure most mechanics forget this and you wind up with that limp mode problem continuing to occur

 

[Hellbettyasaurus]

Maybe someone can help me with mine

I am having this issue as well. It started about 3 months ago, and we replaced the oil pressure sensor. All was well for a while, then right before Thanksgiving, I had the same issue and we have looked at this board for a while, but only created an account today.

Since replacing the oil pressure sensor, we have cleaned both screens (they weren't dirty) and replaced the oil.

The things we have tried are in this order:

Oil pressure sensor
Cleaned small screen
Replaced big screen as it was damaged when we went to clean it
Plugged the wire back into the connector (more on this in a second)

My boyfriend has been working on this with me doing research and youtube videos. So he's actually done all of the work, and I have done the research.

As for the wire coming out of the housing on the connector, it threw the code and he looked at it and he said that the wire was out of the connector, and he literally hooked it up and it worked fine for a few weeks. I purchased pig tails for both connectors, and have yet to install them, as I'm not sure it's the connector.


Where we are as of today:

last Monday it gave me the error again P2647, and we got it home and upon his inspection, he said the connector was covered in oil and he thought that was the problem. So, I'm going to get the stupid o-ring (9139-PAA-A01) and see if that fixes it. He did say that he doesn't think the oil that was/is getting on the connector is causing the issue.

My next step is just buying a whole new VTEC spool valve assembly (15810-RAA-A03)

Any advice or words or wisdom?

 

[Hellbettyasaurus]

Update :

I was looking on ebay for the whole solenoid, and I came across a review for the part,

In that it basically said that he had an Accord, and it was throwing P2646 and P2647, and that he replaced the oil pressure sensor, and cleaned the screens, to no avail.

He went on to say that the actual solenoid on the unit itself demagnetizes over time and that replacing the part fixed his issue.

I think I am going to order one and see if it corrects the problem. I have seen them online for about 40-110, the comment was on one of the lower priced ones.

 

[ToastyRiko]

Similar story:

Diagnosis

My Check Engine Light (CEL) came on, so I took it to Autozone to get a free reading of the code (most auto parts shops will do this for you).

P2647 - Rocker Arm Oil Pressure Switch (VTEC Oil Pressure Switch) High Voltage

The car was driving fine if you stay below 2,500 or 3,000 RPM, but if you start quickly or need more power, the car would shudder and basically not respond until it got back down to lower RPMs.
​

Parts

I read through this forum and watched a few Youtube videos and decided that it was likely the actual switch that was faulty (part #12 in the diagrams you see in this forum). You can search for "Honda 37250-PNE-G01" and find a lot of places to buy them - Ebay, Amazon, H and A Accessories, etc. I wanted to get my Element fixed as soon as possible, and Autozone actually had one in stock at a nearby store, so I picked it up.​

Process

After reading here and watching a couple videos, I saw that removal and installation was pretty easy (though hard to see). You have to reach in the back left, behind the back left side of the engine. You'll see the power steering hose right here, attached with a clamp to the engine. You can unscrew this pretty easily (10mm socket, I believe), and pull it out of the way a bit to get a better look at what you're doing.

In the back, you have a little metal box with an open top (part #6 in the diagram). On the top of it, you have two circular connectors sticking up. The one on the left is...well, I don't know...but the one on the right is the oil pressure VTEC switch. Both of these are just electrical connectors, so you can feel around to push in the on the sides a bit to release them and then pull them up. Once you have unclipped them, you can get go the sensor. This requires a 22mm socket, but it must have a deep head because the sensor is about 1 inch long, so a normal socket won't fit over that to get to the base. Once you have the right tool, you can simply unscrew it and pull it out.

Note that there is a tiny little black o-ring in there. My new piece came with a new o-ring, so I replaced it, and most people would recommend replacing it if you already have the piece out. (It's a cheap little plastic ring, nothing more) So I just put the new o-ring and sensor in, tightened it up, put the connectors back together and then clamped the power steering hose back on.

All in all, the work just took about 15 minutes, IF you have the right tools. I drove the car around for a while, testing it out with quick acceleration (well...relatively quick, considering this is still a 4 cylinder Element, after all) and pushing it where the VTEC would normally kick in. The car responded well, and I drove a bit on the freeway at 65-75 mph to test it out, and I had no issues. About 18 hrs later, after the car had gone through a few cycles of turning off and on and the VTEC kicking in, the CEL went off, so it seems like the problem is fixed!

[Note - many people also recommend taking out the whole unit and replacing or cleaning the screen. That's a good idea, and I'll probably replace that soon, since it's fairly simple to do.]​

Likely Cause

The car had been sitting for a while after a long roadtrip, and I was a bit overdue on an oil change anyway (maybe 1,000 miles over). In addition, I have a minor oil leak, so with all those combined, I'm sure my oil was pretty low and probably a bit gunky. I can't be sure, but based on comments from others, I wouldn't be surprised if that was the main cause of this failure.​

Summary

Parts/Tools - 37250-PNE-G01 sensor, o-ring, 10mm socket, DEEP 22mm socket (DEEP 7/8 in socket also works)
Cost - I bought the sensor and o-ring for about $70 total. You can get one for about $20 online if you are willing to wait for shipping (sometimes from China), or you can buy the OEM ones online for $55-70 (and have to wait for shipping)
Time - 15 mins of actual work, plus I spent about 1.5 hrs reading this forum and .5 hrs watching Youtube videos​

Thank you to everyone who posted here, as you saved me a LOT of time and money, so I wanted to also pass along my experience for others.

 

[Ben10]

Did you ever find a solutions? I replaced oil and filter (Honda) then replaced the entire assembly (Honda) and still the dang problem of shuttering at around 2800 - 3 k rpm has come back. Pretty nervous this is gonna be a black hole for $$$ if I don't find someone who had the same experience.

 

[Ben10]

What did you do to fix this? similar issue I'm having.

 

[Ben10]

The part number on your invoice should be the part number I listed in post #11.

I do not disparage the abilities of a technician that you trust. Unless he has the correct service information available to him, and a scan tool that will allow him to view the operating parameters, it can be difficult to perform a correct diagnosis and repair.

This may help:

The VTEC system increases the amount of intake valve lift for increased power. It accomplishes this by turning a control solenoid 'ON' to allow oil pressure into the VTEC control passages to apply pins that will lock the intake rockers. When the oil pressure is present, the pressure switch signal will go high. When the control solenoid is turned 'OFF', the oil pressure is dumped and the oil pressure switch signal will go low.

simply stated, normal system operation to the PCM would look like: Solenoid 'ON' = pressure switch 'OFF'
Solenoid 'OFF' = pressure switch 'ON'

If the pressure switch signal is not logical for the commanded state of the control solenoid, a DTC will set and the PCM will go into a 'fuel-cut' mode limiting engine rpm and performance. The PCM simply doesn't 'know' what the state of the intake valves are, so you end up with the symptoms you describe.

Clearing the DTC, disconnecting the VTEC oil pressure switch and using a jumper wire to short the signal wire to ground and keeping your RPM below 2700 when driving would prevent VTEC from engaging and you could operate your vehicle. This ASSUMES that you actually do have engine oil pressure to keep from grenading your engine. I assume that you have not had issues with the red oil pressure light in the IP flickering or staying 'ON'? Your particular DTC would not be caused by a low oil pressure issue, but I prefer to be very cautious in this area, since I am not seeing the vehicle first hand and have to rely entirely on 2nd/3rd party information.

The most common VTEC issues we see are, in order of frequency: very low engine oil levels that result in starvation under hard accelleration, faulty VTEC oil pressure switches, faulty VTEC oil control solenoids, sludged / clogged oil passages in the VTEC oil control circuit, wiring harness / connector terminal damage, bad PCM.

The description of pressure switch operation may seem confusing, so compare it to how the regular oil pressure warning lamp works. When you have the ignition 'ON' and the engine is not running, there is no oil pressure. The oil pressure switch is spring-loaded closed (ON) providing a path to ground and the warning lamp stays illuminated. If this was a feedback circuit to the control module, the module would see a 'LOW' voltage because the voltage is being dropped to ground.

When you start the engine, engine oil pressure overcomes the spring tension in the switch, causing it to open (OFF). This removes the path to ground, current cannot flow and the warning lamp goes 'OFF.' A feedback circuit to a control module would see a 'HIGH' voltage potential because the circuit is 'open' - no continuity to ground.

Your 'HIGH VOLTAGE' DTC means that the VTEC oil pressure feedback circuit is staying electrically 'OPEN' all the time. Either the switch is bad, the wiring is broken somewhere, or the control solenoid is leaking oil pressure into the VTEC circuit when it is supposed to be 'OFF' or the PCM is FUBAR.

So helpful.I replaced the oil and filter, than the whole assembly, and still having trouble. It is either because of the others you described.


sludged / clogged oil passages in the VTEC oil control circuit, wiring harness / connector terminal damage, bad PCM.

What should I do next? I could get the other screen cleaned that you have to take a belt off to access.

I'm not sure what is cost effective to do next and concerned about paying a lot of $$$ with a mechanic who doesn't have experience on this type of issue.

Best,

Ben

 

[Fitwise]

I was in southern AZ not long ago and my VSA light came on. Car was starting to shudder at approx. 2800 RPM. If I kept it under 2800 everything was OK. Found a mechanic who replaced part #917-224. I believe it's the variable valve timing solenoid.The next day I drove about 900 miles and it has been working fine since. I never did get the code that was thrown.

 

[Rashinal]

Yes, when the dealer had it. It would randomly lose pressure at highway speed. They were stumped.

 

[keithis11]

Not trying to beat a dead horse...

But I have the old p2646 thing going on currently, have replaced the whole solenoid, not just the oil pressure switch, have been changing the oil every 1000 miles, and for the last 3500 miles or so, I'm still getting the CEL, and for the same p2646. So my question is...
1) has anyone had this issue resolve itself over time with more frequent oil changes? My mechanic seems to think that it will resolve itself this way.(I just purchased the car in January of this year)
2) the issue of not being able to drive faster than 57mph kind of sucks, I have a 47 mile commute to work, and it's mostly highway...does anyone happen to know the top speed of an E with p2646 on, if I do the 6 gear conversion? My car has no other problems otherwise. Thanks in advance for any advice.

 

[Learning]

Vtec

I have replaced said valve with no improvement.

 

[demoderbydave]

I give up

:twisted:
I am beginning to think being a "glutton for punishment" is not for me anymore...

My 07 is far from a virgin at 277K. I have put way more time, effort and money into a 500 buck car than any sane person would. It runs great...when it doesn't have this issue.

I replaced both solenoids with Gates brand parts. Obviously Honda does not build their parts, and these parts are IMHO as good as any of them. It ran great for about 400 miles and then the Christmas tree lit up once again this morning. :047:

I sent about an hour reading all 30 pages of this thread. And my conclusion? it appears that no one really has a cure for this...

It might just be time to move it along to the scrap heap...
But of course I'll spent even more $ on it...:-o

Apparently the rock auto/Gates part I got is defective...it appears to be leaking oil out of the the pressure switch....

 

[Marv]

I don't have the P2646 issue (relatively few miles, well maintained wrt oil changes etc.) but it has shown up a lot in the forum over time and seems quite intransigent in older Elements. At one point it got me thinking about one how to defeat the vtec oil pressure switch with a simple circuit that mimics what it does and prevents 3k limp mode(no emission testing here). Haven't thought about it recently but after the last post I looked to see if anyone had done it sucessfully. Didn't seem so but I saw this: https://www.hamotorsports.com/vtec-pressure-switch-wiring-bypass.html Posted as thought material for the wild and desperate only ;-)