I own a 2000 Accord EX 4cyl the p1259 code keeps popping up I tried fixing the issue many times to the point where I even purchased a new motor just for the car to be fine for 6 months and than boom p1259 code I don’t know what else to do I’ve been dealing with this same / only problem for a year and I’m about to just junk the car. If anyone could please shed some light on my situation it would be greatly appreciated (I even got a new ECU, didn’t help)

 

So a p1259 (which I am sure you know) is a VTEC issue. So I guess the first question, since it's sounds like you have done a lot. Have you checked:

• Faulty Variable Valve Timing and Lift Electronic Control (VTEC) solenoid
• VTEC Solenoid harness is open or shorted
• VTEC circuit poor electrical connection
• Faulty VTEC oil pressure switch

Have all these been replaced?

Thinking outside the box, I've had a poor (but working) alternator create a lot of errors because it's couldn't hold a good enough voltage all the time. Replacing it fixed a myriad of odd issues for me (SRS errors, ABS errors, gauge errors) that had me chasing the problem in the wrong direction.

 

I replaced the entire Vtech Solenoid (OEM HONDA SOLENOID) I didn’t check the harness (the 2 plugs) that connects to the Vtech solenoid. I was going to purchase a voltage meter to test the current going through the harness while the car is running. I also noticed my battery light/ E-Brake light/ door open indicator stays lit it will sometimes turn off but will mostly stay on

 

Hmmm....that might point to the relay.

I've also heard a few times that people have gone under the hood and pulled the "Backup" fuse (I think it's a 10amp fuse), waited a few minutes, and either replaced it or put it back in and the gauges/e-brake lights reset.

The reason for checking the plugs on the harness is they get "junk" in them, oil, debris, etc, or are loose.

At the moment, I still suspect the alternator....that battery light/e-brake/SRS light etc is what happend to me.

 

i actually forgot to mention I have H.I.D fog lights and when I turn them on for the first time they flicker and than eventually stop (they never use to do that before, I just replaced the bulbs there not even a year old) sooo I think your on point with the alternator I think it’s starting to go which could also be the reason like you were saying why my battery light/ E-Brake indicator/ the door open indicator keeps coming/ staying on. Now I’m assuming if the voltage for the Vtech solenoid would suddenly drop while driving the car due to the alternator not being able to supply enough voltage to engage it would that be the reason for it throwing that p1259 code?

 

Yes, I suspect they are all connected. When you have a "whole bunch" [highly technical term] of errors at the same time, it tends to point to a central point of failure for all of them. ECU, main fuse relays, alternator, battery etc. The flickering was yet another item I also had with my lights, at first they would simply dim slightly when the idle was low, and get brighter as I reved up the car but then they started to flicker and all the other lights started coming on. So, yes, it makes sense to me that you won't get anywhere until that is replaced.

Also....and I am sure you won't like this, but you may find that it takes a couple of alternators to get one that is working well. I first bought 1 from Oreilly's it was weak. I bought one from Advanced Auto, it was faulty within a few days and whined horribly from the start. I bought one from RockAuto, which wouldn't even fit correctly in the car. I finally bought a remanufactured original from a guy I found on Ebay you had gotten fed up with aftermarket bad alternators and started repairing and reselling them. That one has lasted with no problems.

On my Civic, the alternator issue was similar. It took two tries to get one. This one came from Rockauto and was fine.

So....just something to keep in mind.

Good luck.