CEL P1259 keeps returning

Evan Wood · Mar 3, 2022

I heard somewhere that this code is a common problem for 6th gens

code was first thrown a few months ago while i was driving (and i was not driving slow) which immediately put my car in limp mode. i got home and restarted the car, it was out of limp but the light was still on. did some research and ended up getting a new VTEC solenoid, and installed it.
after that it was fine for a while but then the code got thrown again, so I took it to my mechanic and he said it he's fought this code before and that its kinda difficult to diagnose.

i make sure the engine oil level is proper very often.

I'm kinda stumped, has anyone else had this issue? and if you've fixed it, how?

Eclipse99fwb · Mar 3, 2022

If you have access to a good quality scanner, monitor what the oil pressure switch is reading. It may be beginning to fail, even if low oil light is not on (basically fools the ecu into thinking oil level is low)
You may also want to pull the vtec solenoid and check the gasket screen, if you have oil sludge it may have clogged the screen.
If those check out okay, you will need to check wiring to the vtec solenoid, had one a year ago that had a loose harness pin no longer making contact on the plug for the solenoid.
Also your vtec solenoid may have failed early, if you have access to a junkyard try to pull a few to test with, i have seen so many new parts bad right out the box or fail only after a few months. Happens more than people think.

Start with this and report back what you find.