mik101

Can someone give a good explanation of exactly how the vtec pressure swtich functions? I'm guessing it doesnt opperate in the same fashion as the oil warning dummy light's switch (grounds out at low pressure) since there are 2 wires going to it instead of 1.

I have a OBD2A B16A2 (Del Sol VTEC) and am using a chipped JDM P30 ecu, so as far as I know it's no longer being used because of the OBD1/JDM ECU.

I was just curious really. Is there a certain pressure at which it will prevent vtec from engaging if I was still using the original ecu?

Thanks!


Modified by mik101 at 2:13 AM 6/21/2007

egsleepercivic

JDm obd1 P30 look for the pressure switch, because they have them(at least mine does, jdm b16a obd 1), i believe the didn't remove the pressure switch until obd2

original ? idk the answer sorry

mik101

Its cool... I'm just going to unplug it tomorrow and see if I get a code. I confuse which motors have which sensors a little sometimes. Thanks.

DIY16KID

just a theory but i think it tells the computer when to send\stop sending oil for vtec by reading the pressure. bypassin it would probally tell your ECU that its alright to send oil all the time. doin that your head would be gettin alot more oil than it should. takin away oil from the bottom end.

Coupe-R

It senses when oil pressure is too low and stops vtec operation to protect the motor.
OBD2 does NOT have this.

P30 looks for this sensor so if you are running a P30 on an OBD2 motor you will get a CEL.

Wire A4-D6 to correct this CEL. No harm done

P.S this vtec pressure switch does not operate as a on off function. Its a variable amount that the ECU reads for this sensor.

HondaPartsHero

The VTEC oil pressure switch is a normally closed switch. The ECM sends a voltage to the switch and expects the voltage to go through the switch to ground. If the ECM reads a voltage on that circuit when the VTEC system should not be operating, it will turn on the "check engine" light and set a code.

mik101

DIY16KID, not really. It's the vtec solenoid which controls the flow of oil to lock the lobes of the camshafts together.

Coupe-R, USDM OBD2 DOHC VTEC motors do, the rest of the world doesnt. (I see you're in New Zealand so yours mostlikely dont, like the JDM motors)

I'm not throwing the code (and never have with either my OBD2A USDM P30 or ny OBD1 JDM P30) so the fix isn't necessary for me. I was more concerned with how the sensor functioned (because if it had been an on/off like the dummy light's switch I was going to use it for an indicator assuming that it had a higher cutoff point than the dummy light's switch).

Does it see oil pressure all the time or only when the vtec solenoid is engaged?

The reason I ask is that if it sees oil pressure all the time and I disable the pressure switch via software (or do the electrical fix for it) then it seems to me that it would be a prime spot for a pressure sender for an oil pressure gauge rather than using the port on the back of the block where the dummy lights switch currently resides (and were I will be sourcing oil for my turbo). I don't want to have to T off the block for yet another sender. I'd rather not have to T anything off there at all (since the dummy lights pressure switch can be removed without issue).

Thanks guys.


Modified by mik101 at 1:10 AM 6/22/2007

Jdmb16sir2

certain 92-95 jdm b16a motor did not have that oil pressure switch. which means that the ecu for those motors where programmed not to look for that switch. the code on the side of the ecu should tell you what program is on it. i asked the same question when i got my 95 jdm b16a and thats the answer i got from steve at H.M.O