Code P2646

[Minfet227]

Trying to get some suggestions. My husband's 2004 civic ex 1.7L is pulling code p2646. Was told to get an oil change to see if that helped, it didn't. The check engine light is on. When you start the car, it starts just fine. As soon as you try to drive it, its pretty shaky. Honda dealer told us to replace the vtec solenoid. Has anyone ever dealt with this? Not sure if the solenoid being bad would make the car run so rough or if we have a potentially bigger problem on our hands. Any input is appreciated

 

[2slo4u]

The solenoid could be the problem as well. Take it apart and clean the screen. That may help. If not, you may have to chance the solenoid.

 

[Minfet227]

Thanks We are going to replace the entire solenoid. Just wasn't sure if the solenoid would make the car act up as bad as it is. Couldn't get a straight answer from the Honda dealer probably because they want us to bring it there to get fixed.

 

[2slo4u]

Thanks We are going to replace the entire solenoid. Just wasn't sure if the solenoid would make the car act up as bad as it is. Couldn't get a straight answer from the Honda dealer probably because they want us to bring it there to get fixed.

No problem. I hope it fixes the problem. Once you bring the car in for them to inspect is when they find more "problems"

 

[HeX]

Dealerships are usually full of morons or dishonest mechanics who want you to drop off the car to then claim you have multiple issues that cost over $1000 to repair. Never trust them

P2646 Honda = VTEC Oil Pressure Switch Circuit Low Voltage
Possible causes
- Check engine oil level and pressure
- Faulty VTEC Oil Pressure Switch
- VTEC Oil Pressure Switch harness is open or shorted
- VTEC Oil Pressure Switch circuit poor electrical connection

If 2slo4u's suggestion doesnt help, then consider the VTEC Oil Pressure Switch.

 

[lowlife9]

it could also be the idle air control valve,EGR,vtec solenoid and throttle body. here is a DIY for all four. http://www.civicforums.com/forums/115-engine/309151-diy-forgotten-tune-up-mods.html
like said in the diy make sure you don't strip the screws on the iacv you should probably by a special tool called a Impact Sccrewdriver to make sure you don't strip them because there as soft as butter. i striped mine when i tried to take them off without the impact screwdriver.

 

[Minfet227]

it could also be the idle air control valve,EGR,vtec solenoid and throttle body. here is a DIY for all four. http://www.civicforums.com/forums/115-engine/309151-diy-forgotten-tune-up-mods.html
like said in the diy make sure you don't strip the screws on the iacv you should probably by a special tool called a Impact Sccrewdriver to make sure you don't strip them because there as soft as butter. i striped mine when i tried to take them off without the impact screwdriver.

Thanks so much Waiting for parts to get shipped to my house. Replacing the vtec solenoid and going from there I guess.

 

[Minfet227]

Okay so changed the VTEC solenoid, car is running fantastic, check engine light came back on pulling code P2646 again. Now what.....

 

[lowlife9]

why did you buy a new vtec i gave you the DIY to clean it because its free and to trouble shoot because it could be multiple things not just the vtec. the vtec always gets dirty and doesn't need replacement just a good cleaning and maybe a gaskit. i gave you the diy so you wouldn't start throwing money at it blindly.

 

[Minfet227]

It wasn't very expensive to replace so we didn't mind. This car is seriously having one issue after another. Replacing the oil pressure switch next at the suggestion of a mechanic. My other question is, would a bad thermostat cause the car to overheat and not produce much heat?

 

[XpL0d3r]

It wasn't very expensive to replace so we didn't mind. This car is seriously having one issue after another. Replacing the oil pressure switch next at the suggestion of a mechanic. My other question is, would a bad thermostat cause the car to overheat and not produce much heat?

Yes, and you can easily test it. Remove it and drop it into a pot of boiling water. See if it opens. Then remove it and see if it closes. If there's no change, it's stuck, and needs to be replaced.