wlanford

I recently had the catalytic converted replaced with an aftermarket (Bosal 099-3672) model. The next day the "check engine (yellow)" light was on. The repair shop said the ecu error code was 22-4. P1259 (VTEC System Failure). They also said this wasn't related to the catalytic converter replacement. They reset the computer. and it was OK for the next couple of hours. However, when my daughter drove the car the same evening, the "check engine" light came on again. It seems like too much of a coincidence that the "check engine" light is not related to the catalytic converter replacement! Does anyone have any knowledge on this subject or suggestions on what I should do now. Thanks in advance!

96jdmaccord

may need to replace the vtec solenoid

-RedneckDave-

You should check all the normal things that will cause vtec to cut out. Oil pressure and level. Check the voltage to the solenoid.

JimBlake

Go to AutoZone & have them read the error code again. If it's P1259 again, I really don't see how that can be related to the catalytic converter.

First you need to make sure your oil is OK. The VTEC system operates on oil pressure, so if it's low, cruddy, old or thin your problem might be just that simple.

4-cylinder??? If so:
Forward & down from the distributor, there's a green plug. That's the VTEC oil pressure switch. With the engine off, there should be continuity between the 2 pins on that sensor.

Above that is a small cylinder sticking up with a one-wire connector. That's the VTEC solenoid valve. It's not supposed to have voltage until the ECU engages it. So the only way to check that is to wire up a meter or test light, in the car; & watch it while driving. It should come on at relatively high rpm, & throttle open.

With a wiring diagram you can check the circuits for the pressure switch & the solenoid valve. You'll need to get to the back of the ECU (forward & down from the radio), backpin the connectors to check continuity from the ECU out to the engine.

That whole assembly on the side of the head is the VTEC spool valve. You can take it off & clean it out, if you suspect it's full of crud. But get all new gaskets for it, they get hard & brittle. One gasket has a screen that might be clogged...

ps...
AutoZone might say that code means something completely different. They can read the code #s, but their list of descriptions can be kinda -um- creative.

98lxaccord

Hey guys, I just need help figuring out what part if the vtec system this is:



My car has the code p1259. My car has trouble shifting at 3000rpm and begins to just pulsate and will not shift into gear when trying to accelerate. I have replaced the vtec solenoid.

The reason I need to know what wire that is, the one that comes from the vtec solenoid, and the wire that connects to it, which looks to be green/yellow, is because on my car, my wire that runs to connect to the vtec solenoid, that is green yellow, looks to be replaced and re wired. I'm wondering if this could be causing my problem with my p1259 code.

I really need help trying to diagnose this problem !