Check Engine Light Documented: Rocker Arm Oil Pressure Switch

mattpuchlerz · #1 (**permalink**) 03-27-2008, 09:38 AM

I was on the way back from a trip when my check engine light (CEL) came on. The car had been driving along nicely up until this—getting around 37mpg at 75mph. I have an auto SSM Sport model with ~33,500 miles.

There was no message in the information screen (the one under the fuel gauge), so I was pretty sure it wasn't just caused by the gas cap being loose. After the light came on, the first thing I noticed was that the cruise control became inoperable. Then I noticed that the car had far less power, and it even juddered once when the engine reached higher RPMs going up a steep hill. My fuel economy began to suffer slightly as well.

I felt comfortable enough to keep driving the car near the same speed, so long as I didn't let the RPMs surpass 3k.

I was able to make it to my destination an hour later, and took the car to a dealer the next morning. They said that the CEL was caused by a faulty rocker arm oil pressure switch. While I couldn't get confirmation from the dealer, I'm fairly certain that the car went into "limp home mode," which could explain the lack of power, fuel economy, and cruise control.

Luckily, another dealer nearby had the switch. Once the dealer replaced it (under warranty), I was good to go. Here is the actual description of what the dealer did straight from the work order:

Quote:

Customer states check engine light on since yesterday.
Scanned code: P2647 - Rocker Arm Oil Pressure Switch Circuit High Voltage, checked oil level was OK; switch internally failed.
Replaced rocker arm oil pressure switch, reset ECM, and performed VTEC test, operating correctly now.
Cleared codes during test procedures.
Part number 37250-PNE-G01

Everything seems to be running fine since then.

Polish · #2 (**permalink**) 03-27-2008, 10:02 AM

Interesting, so the car must have this oil pressure sensor in the head to make sure the top end gets enough pressure? If it falls below a certain # it lets the ECU know.

kirko · #3 (**permalink**) 03-28-2008, 11:47 PM

Its the vtec oil pressure switch. It allows the computer to initiate vtec when it sees enough oil pressure. That is why it was running like crap above 3k, vtec wasnt engaging.

Pumpkin · #4 (**permalink**) 12-14-2008, 04:42 PM

Just got the same CEL myself, and in limp mode the rev limiter resets to 4K. This is nearly exactly what I saw as well. Oddly enough it's taken my car about an hour for limp mode to kick in, and if you turn it off and on it goes away for about an hour. The Autozone guy had a great look on his face when he read the code.

buckswife · #5 (**permalink**) 12-31-2008, 06:37 PM

Interesting, I had this light come on about a week ago and got it fixed last Friday. I was still able to get up to speed, but it had felt sluggish for quite a while and my fuel economy has not been the best for quite a while. I just hit 10,000 miles a few days after the fix.

Pumpkin · #6 (**permalink**) 01-01-2009, 09:59 PM

Of course, when I went to the dealer, the light shut off, but they were able to find the code in the memory. They ran the VTEC checks and all came out well, so they were stumped. In the end, the mechanic speculated it may be due to the non-Honda oil filter I had since the oil was changed elsewhere. They claim to have had that issue with other Honda engines, although this CEL really stumped them. They changed my oil and filter and no issues since then.

kylerwho · #7 (**permalink**) 01-01-2009, 10:55 PM

i think it has something to do with oil levels. just make sure the oil is at the right level and this light will never come back on.

Pumpkin · #8 (**permalink**) 01-02-2009, 11:41 AM

Oil level is one possible cause, but my oil levels were fine based on my check and the dealers'. I think I have a bad switch or maybe it is due to the oil filter as the dealer suggested. I may not see it for a while as it seemed to only happen after 1+ hours of highway driving and I don't foresee any of that in the near future.

gimme · #9 (**permalink**) 01-02-2009, 02:45 PM

Quote:

Originally Posted by mattpuchlerz

I was on the way back from a trip when my check engine light (CEL) came on. The car had been driving along nicely up until this—getting around 37mpg at 75mph. I have an auto SSM Sport model with ~33,500 miles.

There was no message in the information screen (the one under the fuel gauge), so I was pretty sure it wasn't just caused by the gas cap being loose. After the light came on, the first thing I noticed was that the cruise control became inoperable. Then I noticed that the car had far less power, and it even juddered once when the engine reached higher RPMs going up a steep hill. My fuel economy began to suffer slightly as well.

I felt comfortable enough to keep driving the car near the same speed, so long as I didn't let the RPMs surpass 3k.

I was able to make it to my destination an hour later, and took the car to a dealer the next morning. They said that the CEL was caused by a faulty rocker arm oil pressure switch. While I couldn't get confirmation from the dealer, I'm fairly certain that the car went into "limp home mode," which could explain the lack of power, fuel economy, and cruise control.

Luckily, another dealer nearby had the switch. Once the dealer replaced it (under warranty), I was good to go. Here is the actual description of what the dealer did straight from the work order:

Everything seems to be running fine since then.

this happened to me when my car was 2 hours old.

buckswife · #10 (**permalink**) 01-02-2009, 11:28 PM

I was coming back from a long trip when it happened to me too. And my oil levels are fine. I am due up for my 2nd oil change in a couple of weeks. They said it was just a defective part. I bet they just got a bad batch of these parts. I'd be curious if the defective ones from our cars were all made on the same day. Oh well, too late now.

rubixdimension · #11 (**permalink**) 01-11-2009, 02:31 PM

Anyone know if the dealers have issued a TIB on the issue or anything?

sneyeper · #12 (**permalink**) 02-18-2009, 06:31 AM

No TIB as yet that I know of and not at the 4 dealers that I have been to .... they are clue-less and now are probably going to need to buy the car back .... ugh!

S Brake · #13 (**permalink**) 09-15-2009, 09:24 PM

Got my fit on Friday and this same thing happened to my wife yesterday. The problem seemed to fix itself by the time we got it to the dealership. They acknowledged that it was a problem with vtec but that nothing required service. We'll see if it comes up again.

sneyeper · #14 (**permalink**) 09-17-2009, 06:44 PM

S Brake ... did you get a service report from them? ... even though the light went out, they should still be able to see it had the error when they hook it up to the computer ... so, they should have known what the issue was and by clearing the codes that was an attempt to repair. I ended up having 5 different repairs made and they never repaired it ... needless to say, the Fit is still sitting in my driveway waiting on VA courts to hear the case. Hopefully you will have better luck with yours ... One thing I have noticed with mine, having it this long (a year) with the same problem is that it was more prevalent when it was colder outside ... it seems to run much better in warm weather and the light comes on less frequently.

S Brake · #15 (**permalink**) 09-19-2009, 06:43 PM

Their service report said that the rocker arm oil pressure switch had malfunctioned but that there weren't any further problems. We were told that if it did happen again that we should get the part replaced. VTEC is workng fine now and I'll be driving it from Dallas to Lubbock tomorrow so I will have plenty of time to test it out.

leonine · #16 (**permalink**) 10-06-2009, 09:38 AM

mine just went. EXACTLY the same symptoms. started a week or so ago. the car wouldnt go into open loop. every time i tried the CEL would blink then the car would go into limp mode. Then yesterday the CEL stayed on. same code. hesitation and the car stalled once on my way to class last night.

So glad someone posted this. My oil is slightly high when i checked last night. I'll be changing it tonight and swapping out the vtec solenoid and oil pressure switch from my spare engine.