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For those of us who can never go fast enough, uttering the words “my VTEC isn’t working” is one of the most depressing things to say. This problem is usually rears its ugly head by sending an error code (P1259) to your ECU. A few common problems people run into are: insufficient oiling, VTEC pressure switch or solenoid malfunction.
If you ever receive this error, don’t immediately freak out. It’s common for older engines to burn/loss oil (especially the ones which have been abused!). Given enough time you engine will lose so much oil that it doesn’t have sufficient oil pressure to activate VTEC. When this happens, as you could imagine, VTEC stops working and your check engine light will come on. To remedy this problem, simply check your oil level and refill it to full and then reset your ECU codes and you’re good to go.
Okay, so you’ve checked your oil and you’re not low, next thing to check is your VTEC pressure switch. In order to do this you are going to need some electrical skills and a voltmeter. First check for continuity between the two terminals on the switch, if there is none well then you just found your problem. Unfortunately, this is not as cheap as a few quarts of oil so let’s hope there is continuity. I’m all about saving cash were ever possible as I am sure you are too. Now it’s time to test the wiring, while the ignition is ON measure the voltage between the connector terminal #1 (the side with the clip) and body ground. If you are lucky you won’t ready 12 volts, because that would mean you have an open or short to ground somewhere. This is another cheap fix, although it can be a little tedious, tracing and repairing open wires.
You are still reading this! I’m sorry, that must mean you have sufficient oil and a working VTEC pressure switch. There is just one thing left to do for you ambitious do it yourselfer’s, test the solenoid valve. It is a very involved process which usually ends with someone forking over of a large sum of money to a new solenoid. For the sake of saving time, were going to skip a few steps and jump right in and inspect the solenoid for problems. First things first, make sure there is 14 – 30 ohms of resistance between the 1 pin connector terminal and body ground. This step can be skipped theoretically, so long as you checked the wiring to and from the solenoid, but to be thorough lets check it anyways. Now let’s keep our figures crossed for this next step, remove the solenoid valve from the cylinder head, and check the solenoid valve filter for clogging. Now if it is clogged you are supposed to replace the filter, however if you don’t have an extra filter just laying around and you don’t want to buy one you can clean it off with a rag and some brake clean. If this is the case don’t forget to change your oil, you don’t want to get it clogged again. Since you’re already in there push the solenoid valve with your finger and check its movement. As you might imagine, if it is not working properly you’ll just have to suck it up and get a new solenoid if you want your VTEC back.
Well now that you’ve gone through all that I hope all is well in your upper power-band. After all that you should have found and fixed your problem, if not there might be a problem with your ecu. If at all possible swap out the ecu for an ecu you know to be good and re-check. Please note this article is simply a guide, if you don’t know what you’re doing the best thing you can do is get one of your knowledgeable friends to come over and help, or take it to a professional.
