Hello all.............Been away from Honda-tech for a while now, last car was a 97 Accord....Just picked up a new-to-me 04 civic EX.

I am getting error code P2646. Installed a new vtec solenoid and pressure switch. Changed the oil and filter too; that didn't solve the issue.

I have not tested the oil pressure; but the oil warning light never comes on. I think I have narrow the problem to a wiring issue. The brown/yellow wire from oil pressure switch connector is spliced in a couple of places and just doesn't look like it came from the factory like that. I am thinking previous owner installed some sort of device there. I made a video of the issues I found:


Someone please help me get this sorted out. I dont have access to an electrical diagram. Is the wiring supposed to be like that?

Thanks in advance for all your help.

 

Update. .
fixed all the wiring at both the ecu and connector. Check engine light has been off since. I wondered what was installed there before.

 

Hey man,

I've been having this same issue with my 04 Civic EX as well. Do you care to elaborate on how you managed to fix the problem? Like what parts you used to fix it and stuff like that.

Thanks again if you ever see this.

 

Its been over 3 years since that user has even been on Honda-Tech, so I wouldn't get my hopes up.

 

That's really unfortunate because this is my exact problem and I can't seem to figure this out

 

Hope you figure out where in the circuit the failure is. Electrical faults can be tricky.

 

Hello,

I fixed the problem by grounding the Vtec solenoid permanently. I no longer have the vehicle but I think I disconnected the connector to the solenoid and grounded it at the pcm.

Look on Youtube for grounding the vtec solenoid.

 

Were you still able to use VTEC? I haven't been able to find many videos on it. How did the car run after you did that?