Nakinto

So I am getting the P1259 code, but only after 20 minutes of driving on the highway... I lost 5th gear a LONG time ago and haven't been able to replace the transmission (have a spare but no time to swap them...)

I have proper oil level, I have good oil pressure, I replaced oil and filter (problem started before replace), Checked wires and the solenoid and oil pressure switch, all checked out. I am unable to check the solenoid while driving though... Is it possible the solenoid is heat failing? I know my Cruise control relay is... but that is a relay and Cruise isn't necessary... The symptoms are almost identical... Cruise for 15-20 minutes then BOOP no more cruise until the car cools down... VTEC for ~20 minutes then BOOP P1259 until the car cools down... Yes, I reset it while driving... just pulled over, ran the OBDII tool, reset keep driving as soon as I hit 3300 RPM BOOP P1259 again :*( And of course P1259 puts the car in damn limp home mode (no more then 60MPH or 4000 RPM...)

Wankenstein

P1259 code info: https://www.engine-codes.com/p1259_honda.html

Remove the Vtec solenoid and clean (or replace) the Vtec solenoid gasket screen and the solenoid itself with brake cleaner spray. Reinstall and hope for the best.

ezone

What number, how many PSI is GOOD?
My pressure gauge has a bunch of numbers on it, not words. LOL


Do you know what the oil pressure specs are?



You checked pressure on a cold engine, or what?



Check oil pressure, monitor it and see what it's doing when it trips the code.
20 minutes is about when the oil is getting hot and thinning out, so......after it gets the oil hot the pressure could really be too low to keep the switch contacts (open or closed, whichever) while vtec is on.

There's a special tool to adapt a pressure gauge to the vtec pressure switch port. If the oil filter is restricted there would be a large pressure difference between measuring at the idiot light switch and measuring pressure at the vtec pressure switch.

If you really think the solenoid is going bad when it heats up, measure the amperage it's using while it's in operation. See if it changes dramatically just before it trips the fault code.

Nakinto

That is a good suggestion Ezone. Sorry, I didn't include this in the op.

I used the Honda service manual guide
https://www.civicforums.com/forums/1...lfunction.html

Love these forums I rarely have to actually ASK any questions

Oil pressure is at 61 PSI at the dummy light... I haven't bought the special adapter yet, but as I stated I did this before and after replacing the oil filter to rule out the filter being the cause. I see what you mean that 20 minutes the oil is thinning, not sure that should cause this I use full synthetic "high Mileage" 5-20 weight. (the recommended) I have used that since I purchased the car at 156k now at 312k (replaced engine at 186... previous owner didn't change the oil... Blew a BIG whole in #2 cylinder...) I recently had to replace the Cat, engine was having issues and when I checked the exhaust pressure... WOW at 3000 rpm the back pressure just spiked...

Megalodog, I have NOT replaced or even checked that screen... I will have to get new seals and take it off again, at least it is easy to remove... I will do that in 3 days (I work weekends and the spare has a big whole in the rear brake line...)

Again, Thank you guys for your help! I love it!

ezone

Check path of oil flow. On most engines the idiot light switch is located (hydraulically) between the pump and filter, instead of between filter and gallery.

==============================================

From your link to the other post, they want to make sure it's got more than 57PSI at the vtec valve when hot and 3000 RPM:

Step 19) Remove the VTEC oil pressure switch (A), and install the special tools as shown, then reinstall the VTEC oil pressure switch


Step 27) Start the engine and check the oil pressure at 3,000 rpm
Is the oil pressure above 390 kPa(4.0 kgf/cm^2, 57 psi)

===============================================

Doesn't matter. It's still 5w20w oil.
Hmm. Q&D check might be to just fill the oil with 10w40 and see if that keeps the code away?

Nakinto

Well I did JUST replace the oil But that is a very good idea... I might try that...

I Think I am going to be forced to have the shop check the pressure at the Solenoid (I am NOT spending $300 on an adapter... that is highway robbery! ) If the pressure comes back good while warmed up I am going to take off the solenoid and check it, if it is clean etc, I am going to just replace it ($150 on Rockauto...)

Thank you guys for the suggestions

ezone

I'd bet almost no shops or mechanics will have the adapter needed to do that. Not many dealers either.

You'll hear "YES" over the phone, but onced you actually drop the car off it's a different story........

Nakinto

Additional Information. While driving to work today, the main freeway is closed, my drive came to a crawl... I reset my computer (P1259 hit again...) and after getting back up to 70mph it took 18 minutes for the code to re-appear... I started the timer after I hit 3200 RPM.

Any insights? This seams very strange to me, unless the computer only checks every 20 minutes or so for the signal... I really don't know how the ECM and the VTEC system code works...

ezone

no, it's constantly monitored and IIRC it takes about 5 seconds with the pressure switch in the wrong state to trip the code.

Slumpertcivic

Nakinto

So talked to my mechanic and two local dealerships. None of them have the equipment to do the oil pressure check for this... On the way to work though, in 90+ temps P1259 didn't trip until almost 40 minutes into the drive... I wonder if there could be a piece of metal in the line or an air bubble? If tonight the code isn't thrown for longer then I am going to leave it this weekend (I have M-Tu off) and see what comes from it through next week. I will still be ordering a new Solenoid (Honda gives weird names to things... says this isn't a solenoid...) and if the issue resolves itself I will have a spare part in a bag with my other spare parts... (MAP, TPS, Complete Head, 'newer' injectors etc)

Thank you guys for the assistance and the knowledge. MUCH APPRECIATED!

Slumpertcivic

Nakinto

4000 RPM typically. Always above the 3200 RPM switch. I don't have 5th gear due to wear and tear on the transmission... This is also probably the cause of the Vtec issue as it has had to be on MUCH more then normal...

Slumpertcivic

Nakinto

Great idea! Thank you for the suggestion. But after checking all the local junkyards... No junkyards near me have a 7th gen Honda... let alone a Civic... Apparently these cars just don't die... Not sure if I am happy or mad about that...

Any idea of other years that might have the same Vtec solenoid?

ezone

Oh they get sent to the boneyard here. your local might crush them right away lol


Yea the time element makes it sound like it could be a bad winding in the solenoid. I thought I mentioned using an ammeter to monitor current, but that's not all that easy lol

01-05 civic with vtec all use the same for sure



FWIW the pcm does not monitor the solenoid current so it can't tell directly if it is in control, the pcm only monitors the vtec pressure switch and uses that info to judge if the system worked

Nakinto

Ezone, you did mention it (not sure if it was here or elsewhere) I just am not sure how I am going to go about DOING that you know? it isn't like these plugs are... interchangeable or easily found... I have no clamp on ampeter so I would have to put it in-line (I am certain it shouldn't be more then an amp... I COULD cut the line I guess and then shrink rap it back when I am done...

ezone

I wouldn't cut wires unless absolutely necessary. I have enough terminals and wire laying around to construct a jumper or extension cord that would connect to the stock wiring without damage.


Other than cost involved, it's probably much easier to bolt on another unit and see if it works.

Nakinto

Well, Ezone, It is definitely a failing coil... The heat shrink/cut idea gave me a better one... Heat shrink a wire to the plug and put the meter in between the two sections needless to say... 13 minutes into use (Vtec system) the meter spiked to 12 amps... and I pulled the plug on the meter... It appears the Vtec solenoid is shorting out as it heats up... FUN TIMES

Again, thank you guys for all the help! It is has been much appreciated.

JonathanPR

Hey guys, I’m late in this conversation but, I have the same problem, after 20-25 minutes my car drop p1259 and the car won’t pass 4K rpm, your problem was the vtec selenoid or a bad coil? Thanks!

sdaidoji

iTrader: (1)

1st step - check oil level!

Nakinto

First holy necro batman!
Now, it was the Coil in the solenoid. The entire solenoid had to be replaced