Rep Power: 0

Little backstory, as i was driving on the freeway and as I went up a mountain on a two hour trip, my honda civic 2003 ex wouldn't speed past 4000 rpm; the car would just stutter. It would do the same thing just going up the mountains.

Scanned for the codes and got p1259 manufacturer control. Erased the codes and I just did city driving, code didnt pop back on.

Went ahead and replaced the VTEC solenoid. After this I test drove it and the same code popped back on immediately. I did a oil change last month so it shouldn't be bad oil. Can anybody assist with what I can do next? Would it be the VTEC oil pressure switch or something more complicated?

 
Rep Power: 518

Needed to be aggressive enough to engage vtec several times.

Used? New aftermarket? New from Honda?

Uh, your original did not set a code immediately. I'd assume the new valve came with an entirely new problem?. Put the original back on it to check?

You probably wouldn't believe how many times I've fixed that code with an oil filter .

 
Rep Power: 0

Appreciate the feedback. I bought the part off of Ebay, looked new. I recieved the same code for when I first had the problem and when I replaced the solenoid. Only it was the second time that the code came back on immediately.

I installed full synthetic oil with a good WIX oil filter. If it's the oil filter thatd be a shocker to me, haha.

Is there any other possible reasons that this code might be popping on? It surprises me that I cant seem to find adequate information about it. I even own a Haynes repair manual that doesnt even touch on it.

 
Rep Power: 518

What the computer looks for is simple. It needs to see the pressure switch change after it turns on the solenoid. And it needs at least 50 psi oil pressure when on.
When the solenoid is turned on, the pressure switch is supposed to turn off within something like 5 seconds. And vise versa, solenoid off=switch on.

Basically the ecm sets the code if the pressure switch is in the wrong state at the wrong time.
That's, like only 4 combinations of on/off the ecm can look for?
It's up to you to figure out why and fix it.

The solenoid controls the hydraulic valve, oil pressure goes through valvetrain parts and hopefully makes vtec kick in yo, and then the pressure switch operates if it receives 50 psi during vtec kicked in yo..
But the rest of the system is not all that simple, there might be dozens of different possible causes for the code but just a few are common.


The easiest and the worst problem is when low oil level causes the code.. It's tough to maintain over 50 psi when its 3 quarts low on oil.

 
Rep Power: 0

This is a very thorough explanation of the system. Highly appreciate this.

I might end up having to take it in to a trusted mechanic who may have a good scanner and alot more knowledge than I do to plan my course of action.

Thank you.

 
Rep Power: 518

If the new valve causes code immediately, but the old valve did not, I'd assume the new part is at fault. Unless you have a wiring problem.
If it resets the code immediately without having to drive around, i think the ecm didn't see the switch input grounded at keyup and idle..... , the pressure switch could be bad or incorrect, or just unplugged.

 
Rep Power: 0

Got an update from two mechanics, they believed that the car timing belt jumped a tooth going above 4000 rpm. Not the problem I expected but gonna cost be 500 dollars to fix... just gonna have them replace the timing belt, tensioner, and water pump if they're gonna have to go down their and adjust everything anyway. They believe that bad timing was triggering the code to come back on immediately.

 
Rep Power: 518

P1259 is not caused by incorrect cam timing.

 
Rep Power: 224

Did they actually check the timing? It can be easily checked.

 
Rep Power: 0

So the reason they believe it could be timing is through a couple of things.

- The code came back on immediately after I put in the new solenoid. I even transferred the old VTC sensor to the new one on my 3rd attempt to put the solenoid in, same thing.

-when I drove my car to the shop, it didnt sound very good.

-the mechanic i took it to noticed I had my head refurbished, which I did as I had a blown head gasket about a year ago. The mechanic believed the car was never timed right after that..

.. that's when I gave my other mechanic a call (the one who did my gasket) and they asked me about what the mechanics did. He even asked me if they checked the belt.. and after calling them they were going to upcharge me 300 bucks to do that. But after telling my mechanic what was going on, he believed that when I was driving my car up here to Flagstaff, where there is a lot of hills to go up, that i pushed the motor too hard trying to go past 4000rpm, and thus he believed the car skipped a tooth... causing the timing to be incorrect and low oil pressure to affect the vtec solenoid.

And since the shop was charging me 700$ to adjust the timing, I might as well just let them replace the belt n ****. Since I already had those parts it came down to 500.

But I hope they are right.. are there any other possible things that could be triggering this code?

 
Rep Power: 224

They thought the timing was off because it was running rough and the head gasket was replaced a year ago It's like a 15-30 minute job to check timing. If they haven't started the work yet I would recommend finding another mechanic.

Like Ezone said that code isn't caused by cam timing. Unless there are other faults now this won't fix your issue.

 
Rep Power: 0

I'm assuming that bad timing wouldn't affect oil pressure then (or at least in case of VTEC)? Most mechanics are going to charge me up here just for a regular diagnosis, I guess I'm spending money either way.

 
Rep Power: 224

Nope. Even if it were off a tooth the oil pressure should be okay.

 
Rep Power: 0

Interesting. Im gonna call the place and see EXACTLY what they did to rule it out..