[Aviator08]

Thanks for the feedback John. One thing I wanted to mention was that in order to prevent this from happening while on long drives I will hold the brake with my left foot and slightly hold the gas down to about 1000RPM to keep the oil pressure up. This prevents if from going into the "limp mode". I suspect that it must have something to do with the oil pressure but I am not sure why it is happening. Anyways I thought I would share this to see if it helps with the diagnostics.

 

[Victoriusvega]

Were you able to get it fixed, this just started happening to my 05 odyssey exl. I recently got an oil change at valvoline and 200 miles after the check engine came on but also the VSA and it rattled a lot. Once I turn off the car and turn it back on the VSA light turns off and the rattling stops, about 90 miles later the check engine light turns off and repeats140 miles later. With a code P2647. Any suggestions? The oil used was 5w20

 

[John Clark]

Were you able to get it fixed, this just started happening to my 05 odyssey exl. I recently got an oil change at valvoline and 200 miles after the check engine came on but also the VSA and it rattled a lot. Once I turn off the car and turn it back on the VSA light turns off and the rattling stops, about 90 miles later the check engine light turns off and repeats140 miles later. With a code P2647. Any suggestions? The oil used was 5w20

Check your oil level.

 

[schneidm]

The way the system works is the solenoid is commanded on and off by the PCM. When the rocker arm control solenoid is commanded off (during 6 cylinder mode) it sends engine oil pressure to the rocker arm oil pressure sensor. That's how the system knows the VTEC/VCM system is off. When the system goes into cylinder pause mode the solenoid is activated and the oil pressure to the rocker arm oil pressure sensor is removed. That's how it knows it's on.

Essentially, either the solenoid is not turning on or the solenoid is turning on but the pressure sensor is not seeing it.

I am diagnosing a P3400 code on my 2008 Touring model. Does your technical explanation apply to VCM systems as well? In other words, the oil pressure switch only receives oil pressure when the oil control solenoid is OFF, and when the VCM is activated and the oil control solenoid is ON, the pressure is removed from the oil pressure switch such that it turns OFF? I have bench tested my switch. I know it is a normally OFF switch and it does work when pressure is applied. If your explanation is true, that means I AM getting oil pressure to my VCM system, and my problem is with one of the two solenoids (rear bank).

 

[dvpatel]

I am diagnosing a P3400 code on my 2008 Touring model. Does your technical explanation apply to VCM systems as well? In other words, the oil pressure switch only receives oil pressure when the oil control solenoid is OFF, and when the VCM is activated and the oil control solenoid is ON, the pressure is removed from the oil pressure switch such that it turns OFF? I have bench tested my switch. I know it is a normally OFF switch and it does work when pressure is applied. If your explanation is true, that means I AM getting oil pressure to my VCM system, and my problem is with one of the two solenoids (rear bank).

John's post you quoted is for the VCM system actually. The below from his quote is a dead give away of the fact that John is talking about VCM.

When the rocker arm control solenoid is commanded off (during 6 cylinder mode) it sends engine oil pressure to the rocker arm oil pressure sensor.

 

[dhausman]

You ever figure this out? I have an 07 and the VSA and P2647 seems to pop up when putting it in Park. I changed oil, replaced the oil sensor, replaced inner and outer gaskets on the solenoid, checked filter and it was clear. Oil level is good but I am stumped.