Rep Power: 0

Hello. After full engine service, i'm already half years matching with this problem. On 1st and 2nd gear vtec works perfectly, no check engine comes, on the 3rd gear, I push the car to 4,5 5k rpm, and it's slows down, then I get check engine, and I can't push car over 4k rpm anymore. After I start the car again, check engine is iliuminated, but the vtec works again on 1st and 2nd gear, when I hit 5k about rpm on 3rd gear, it slows down me, and don't let me push over 4k rpm in any gear.

I did already a lot things-
checked the whole vtec solenoid, pressure switch, resistance and all the thing I should know - everything perfect
The diagnostics shows me that there have been P1259 vtec fault and exccesive speed change.

One crazy thing, that when I turn off the connection of my speed sensor, the car lets me push over 4krpm everytime and everything works perfectly, except I get EPS illiuminated (steering is electric, and it must see the speed)

So could you help me pls? I have no idea what is going on...

Oil also was as needed to be.

 
Rep Power: 126

What year is your civic? That’d be a good place to start.

 
Rep Power: 0

2003 year
7gen
ep2
1.6i

 
Rep Power: 225

That sounds like a great place to start. VTEC won't engage if the vehicle speed isn't working properly.

 
Rep Power: 0

well yes, I thought about the same, but the vehicle speed sensor gear looks pretty good. Is it possible that the problem is electrical? I mean, maybe even if my speed sensor works good, shows me the speed properly, but it doesnt give a good signal to ECU what makes me feel the vtec failure?

 
Rep Power: 368

then you check the wires and connectors

 
Rep Power: 0

maybe anyone knows where I could get wiring circuits diagram for my car?, autodata dont show me the vtec and ither things.

 
Rep Power: 225

I think the normal service manual still applies. See the link below for the thread.

https://www.civicforums.com/forums/1...pdated-12.html