Like the title says, I'm getting a check engine light everytime I lower my VTEC changeover point with my VAFC2. I've tried this twice now and both times got the same result. I set the VTEC this last time for a lo-hi changeover at 5000RPM and a hi-lo at 4800RPM. Two trips later (I understand that it actually takes two times for a malfunction to be stored as a CEL) I got a CEL. Basically I was crusing in third gear, went into VTEC and got off the throttle around 5300RPM to slow for traffic ahead, it was like the car was stuck in VTEC for a minute even though my foot was off the gas. As VTEC disengaged the CEL came on. I got home and pulled the code, it was a code 22 which is a VTEC system malfunction. Someone suggested to me that the VTEC changeover can't be set while the engine is running... I've confirmed that's not the case because I didn't have the motor running last time I set the values and still got a CEL. I'm guessing that maybe some other value has to be set in the VAFC2 for this to work properly, maybe the fuel correction at VTEC unmatch?!? Anyone have any thoughts as to what might be going on and how to correct it??

If it matters, my car has not been tuned with the VAFC2 yet, that's scheduled to happen at the end of this week.

 

did u hook up the VTM wire? that goes to the ecu side of the vtec pressure switch pin.

 

I think code 22 is VTP more specifically. The pressure sensor on the VTEC solenoid needs to see 55-60 psi before it will engage VTEC. You should have plenty of oil pressure at 4800 RPM, but for some reason your oil pressure is low. Try thicker oil, less restrictive oil filter, or maybe take off the VTEC solenoid and check the screen in the gasket, or the pressure sensor itself. From there inspect the oil pump, bypass spring, etc...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">I think code 22 is VTP more specifically. The pressure sensor on the VTEC solenoid needs to see 55-60 psi before it will engage VTEC. You should have plenty of oil pressure at 4800 RPM, but for some reason your oil pressure is low. Try thicker oil, less restrictive oil filter, or maybe take off the VTEC solenoid and check the screen in the gasket, or the pressure sensor itself. From there inspect the oil pump, bypass spring, etc...</TD></TR></TABLE>

You could be on to something. I checked my oil level and it was low, but still that doesn't explain why everything works fine when i restore the VTEC settings to defaults.

 

The default VTEC changeover points might be high enough to where you have built up enough oil pressure to engage VTEC even with your low amounts of oil and/or dirty VTEC solenoid, but maybe at a lower RPM you have not built up enough oil pressure because you have low oil or a dirty solenoid, etc. Just a possibility...

 

Both times i got CEL's it was when my car was coming out of VTEC. The car has no problems activating VTEC, even when the changeover point has been lowered, it's when it goes hi-lo cam the problems occur. I'm not sure oil pressure should have any effect on that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">The pressure sensor on the VTEC solenoid needs to see 55-60 psi before it will engage VTEC.</TD></TR></TABLE>
This isn't entirely correct. The vtec pressure signal is not a requirement for solenoid activation, it is merely feedback for the ecu that the high cam lobes successfully engaged when it attempts to activate the vtec solenoid.

mike1627, have you double checked the wiring? What you are describing is symptomatic of an improperly/not connected VTM wire.

 

I double checked everything after i finished installing it so i'm fairly sure it's not the wiring. It's not like the VAFC2 isn't working, it works great if i really get on the throttle. Both times I triggered the CEL it was when i was just crusing at a high RPM and went into and out of VTEC rather quickly.

 

To the people who said it was the VTM wire.... you were right

Apparently the VTM wire isn't shown for some ECUs in the wiring diagram that ships with both the VAFC and VAFC2 so I never had it connected thinking it wasn't used. I had to tripple check everything and place a phone call to Apexi before they told me there is an updated wiring diagram online that includes the VTM wire.

 

Hehehe told you so