Rep Power: 0

I was getting P1259 (CEL 22) permanently. After a reset the code would start flashing as soon as I turned the ignition on, even before starting the engine. I figured the problem must be a bad V-TEC pressure sensor because how could it actually detect pressure without the engine running? So I decided to bypass it under the hood which worked. Sorta. I first took some 26 gauge kanthal wire I have lying around and jumpered the port that plugs into the lower part of the V-TEC, the blue and grey wires I think. The code went off but would then come back randomly, usually when accelerating past 4500 RPMs on the highway. I thought maybe my crappy jumper was losing contact from vibration so I went about trying various methods of jumpering it. I tried twisting and doubling up the kanthal, I tried speaker wire, I tried placing the connector into the V-TEC to try to hold the jumper in... nothing worked. I can't say for sure but it did seem that some methods worked better than others because some methods seemed to give me more time until the code came back.

I finally just clipped the port off (ouch!), stripped back some of the insulation on the wires, and wrapped them up together tightly and then wrapped that in gorilla black electrical-type tape. This gave me the best results but still the code comes back. Fortunately I did get it to stay long enough to pass my past-due emissions!

AFAIK there's nothing more to this circuit than going between the ECU and the V-TEC pressure sensor. Is that wrong? I'd like to jumper it 100% properly so I can be sure it's not crappy connection I've made. How do I do that? Do I need to run an extension cord to a soldering iron or should I use one of those electrical plastic crimps? I don't see how the circuit could break with those wires wrapped like that. Assuming the connection there is fine would this indicate there is something wrong with the wiring between the V-TEC and the ECU? Could the ECU have a problem?

After I make sure the connection under the hood is good (how do I do this?) I suppose the next thing to try would be to do the bypass at the ECU. This makes me nervous because I'm not experienced and could make a mistake stripping back the insulation here and that would be big headache for me, so I'd like to make sure there's nothing else to try before I resort to this.

It's very annoying to have to get out and reset my ECU every 5-50 miles.

 
Rep Power: 367

engine oil enough?
car-part.com for scrapyards nearby, get a solenoid there to test

 
Rep Power: 0

The solenoid pressure switch has been bypassed completely, as I described in the OP. The actual solenoid valve is still connected but AFAIK that part only throws CEL 21, not 22.

Is it possible to get CEL 22 (P-1259) when the v-tec pressure switch is bypassed? I don't believe so but I'd like to find out what others say before I determine that the problem is in my ECU or the wiring between the ECU and the v-tec pressure switch port.

 
Rep Power: 224

Isn't it easier to just fix the issue instead of trying to bypass?

 
Rep Power: 222

Agreed, undo all of your hackery, fix it properly

 
Rep Power: 0

Okay but would doing it properly actually make the code go away? If there's a short in my wiring or a problem with the ECU what good would replacing a closed part of the circuit with a switch? I agree that it's better not to just pull parts and functionality out of my car and I do plan on replacing the pressure switch and making everything whole but at this point it would seem that there is a problem that isn't the pressure switch itself.

 
Rep Power: 229

-Vtec error only shows at appropriate rpm +3400

error can show for
-low oil
-bad oil pump
-no power/ground/blown fuse, to solinoid
-clogged solinoid filter
-internal errors like missing parts on the rocket assembly, or failure to engage vtec pins on the rocker arm assembly (could be caused by letting the oil go low, with carbon lockup)

You will always have issues with vtec bypass since the fuel map is changed within vtec range. So no vtec will cause rich fuel conditions, the ecu will lean it out, then you'll be lean while normally driving. Yo-yoing back and forth.

 
Rep Power: 224

ECU may also think the switch is shorted (which it is). It closes when there is enough oil pressure. If it sees it closed when there is no oil pressure (just key on, engine off) it may through a fault.

 
Rep Power: 367

i feel we have a winner

 
Rep Power: 0

Thank you! I see that I was woefully wrong thinking I could just bypass this problem away.

I can rule out low oil (i have a dipstick) and problems with the solenoid itself because that's been bypassed. I have let the oil get low in the past so it could be coming from the problems with the locker arm. Unfortunately I have no idea how that stuff works so I might have to get it looked at. In the meantime I'll learn how to check toe oil pump.

 
Rep Power: 0

The code always gets thrown while the engine is running. Usually when accelerating on an on-ramp in third gear at 3-4500 RPM. 3/4 times it happens under these exact conditions and I'd say 100% of the time it's when I'm accelerating and at 3-5000 RPMS in any gear.