vtec oil pressure switch
11-23-2003, 12:44 PM
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vtec oil pressure switch
i've read on this board only once of a bypass for the vtec oil pressure switch. currently i have a jdm d15b in my 92 hatch, everything is wired fine and it runs well. however, i still have a CEL, due to the remaining missing vtec oil pressure switch... to my knowledge the p08 ecu did not look for the switch, but the p28 i am running does.
are there any ill effects to bypassing the switch? vtec will only be engaged if the car is warm, and i do not plan to tamper with that... if it is safe, what pins/wires on the ecu will i have to splice into eachother?
EDIT:
500
are there any ill effects to bypassing the switch? vtec will only be engaged if the car is warm, and i do not plan to tamper with that... if it is safe, what pins/wires on the ecu will i have to splice into eachother?
EDIT:
500
11-23-2003, 04:49 PM
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Re: vtec oil pressure switch (FlatLineEG8)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FlatLineEG8 »</TD></TR><TR><TD CLASS="quote">Vtec oil pressure switch is the devil
</TD></TR></TABLE>
care to explain?
</TD></TR></TABLE>
care to explain?
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11-23-2003, 08:11 PM
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Re: (ShadyEH2)
i know d6 is one of them... but the other is a ground and i dont know which one...
vtec oil pressure switch is not in hand, so i wouldn't know... .
help out! tryin to run vtec!!
vtec oil pressure switch is not in hand, so i wouldn't know... .
help out! tryin to run vtec!!
11-23-2003, 08:15 PM
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Re: (jdmsiR20)
The P28 ECU plugs right in, you all you’ll need to do is wire the VTEC up. First, you’ll need to get an engine plug from a junkyard for the VTEC solenoid oil pressure.
You can see mine here, it’s big and yellow:
Here is what the back of your ECU plugs look like:
You’ll need to run the blue wire (or whichever color is from the plug) to pin D6, and then run the black ground wire from the plug to anywhere on the motor. You then need to run the green wire from the VTEC solenoid to pin A4.
You can see mine here, it’s big and yellow:
Here is what the back of your ECU plugs look like:
You’ll need to run the blue wire (or whichever color is from the plug) to pin D6, and then run the black ground wire from the plug to anywhere on the motor. You then need to run the green wire from the VTEC solenoid to pin A4.
11-23-2003, 08:27 PM
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Re: (boostedcivicsir)
all the above is correct 
but... is it safe to bypass the switch? i've read that you can take the blue wire (or whatever goes to d6) and splice it with the wire at a4... any truth? i will be picking up a switch later on, but can i do that temporarily? i'd really like to have this going, its been too long!!!
but... is it safe to bypass the switch? i've read that you can take the blue wire (or whatever goes to d6) and splice it with the wire at a4... any truth? i will be picking up a switch later on, but can i do that temporarily? i'd really like to have this going, its been too long!!!
11-23-2003, 08:46 PM
#12
Re: (jdmsiR20)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmsiR20 »</TD></TR><TR><TD CLASS="quote">all the above is correct
but... is it safe to bypass the switch? i've read that you can take the blue wire (or whatever goes to d6) and splice it with the wire at a4... any truth? i will be picking up a switch later on, but can i do that temporarily? i'd really like to have this going, its been too long!!! </TD></TR></TABLE>
I don't think that is a good idea. A4 is the VTEC solenoid output, and that is a 12 volt signal when the VTEC is active. I believe the input at D6 is looking for a ground when there is oil pressure. You should try wiring the blue/black to the oil pressure sensor on the back of the motor, next to the oil filter. That sensor has a ground output when there is oil pressure. It is for the low pressure indicator in the gauge cluster. The reason this is not a good option for the long run, is because for reliability reasons the oil pressure for the VTEC should be monitored at the head.
but... is it safe to bypass the switch? i've read that you can take the blue wire (or whatever goes to d6) and splice it with the wire at a4... any truth? i will be picking up a switch later on, but can i do that temporarily? i'd really like to have this going, its been too long!!!
</TD></TR></TABLE>I don't think that is a good idea. A4 is the VTEC solenoid output, and that is a 12 volt signal when the VTEC is active. I believe the input at D6 is looking for a ground when there is oil pressure. You should try wiring the blue/black to the oil pressure sensor on the back of the motor, next to the oil filter. That sensor has a ground output when there is oil pressure. It is for the low pressure indicator in the gauge cluster. The reason this is not a good option for the long run, is because for reliability reasons the oil pressure for the VTEC should be monitored at the head.
12-05-2003, 03:20 PM
#15
Re: vtec oil pressure switch (jdmsiR20)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmsiR20 »</TD></TR><TR><TD CLASS="quote">are there any ill effects to bypassing the switch? vtec will only be engaged if the car is warm, and i do not plan to tamper with that... if it is safe, what pins/wires on the ecu will i have to splice into eachother?</TD></TR></TABLE>
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.
12-05-2003, 05:49 PM
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Re: vtec oil pressure switch (VTECVillain)
^ great!!! thanks... now i dont have to run out and buy a switch!!!... i will have my vtec tomorrow!!!
12-05-2003, 06:21 PM
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Re: vtec oil pressure switch (VTECVillain)
when i first hooked up my mini me useing a p08 ecu it threw a code for vtec oil pressure switch. i just took that wire added a connector and bolted it down to a ground. it worked fine till i wired up the switch. how the switch works is...you have 2 pin outs on the switch. one goes to the ecu and the other goes to ground. when you get enough oil pressure the switch closes and basically connects the 2 pins together. since you have one end going to ground when they "connect" the ecu sees a ground and will then allow for a 12v signal to be sent to the vtec solinoid. you by no means want a 12v signal going to the oil pressure switch, this will cause some serious damage (a short).
12-05-2003, 06:50 PM
#18
Re: vtec oil pressure switch (FMIDRC Racer)
What you say is logical but it doesn't have anything to do with the method I've described. When you take the wire at D6 and tap it into A4 this in no way will cause a short. The wire at D6 is cut then the ECU side is tapped into A4 which makes the other end of the wire going out to the engine bay lay dormant.
This isn't some crazy method I came up with, I learned this from Kenji. He knows a thing or 3 about ECU chipping, tuning and electrical schematics and has been doing this for a very long time. Just ask around I'm sure you'll hear the same thing from others.
This isn't some crazy method I came up with, I learned this from Kenji. He knows a thing or 3 about ECU chipping, tuning and electrical schematics and has been doing this for a very long time. Just ask around I'm sure you'll hear the same thing from others.
12-05-2003, 08:45 PM
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Re: vtec oil pressure switch (FMIDRC Racer)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FMIDRC Racer »</TD></TR><TR><TD CLASS="quote"> how the switch works is...you have 2 pin outs on the switch. one goes to the ecu and the other goes to ground. when you get enough oil pressure the switch closes and basically connects the 2 pins together. </TD></TR></TABLE>
You have that backwards. The VTEC switch is normally closed. When the oil presure gets high enough, the switch opens.
You have that backwards. The VTEC switch is normally closed. When the oil presure gets high enough, the switch opens.
12-06-2003, 12:10 AM
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Re: vtec oil pressure switch (Chiovnidca)
kool thanks... i understand the above, switch is normally closed, and 12v power when its open... got it!! i'll let you all know how d15b power feels real soon!!
04-05-2004, 08:40 PM
#21
Re: vtec oil pressure switch (VTECVillain)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECVillain »</TD></TR><TR><TD CLASS="quote">
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.</TD></TR></TABLE>
So all you really have to do is create a jumper out of a piece of wire and run it from D6 to A4? If that's the case, that's easy to do.
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.</TD></TR></TABLE>
So all you really have to do is create a jumper out of a piece of wire and run it from D6 to A4? If that's the case, that's easy to do.
04-11-2004, 04:27 PM
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Re: vtec oil pressure switch (zgrieger)
hey .. i got a question.. im kinna confused....about this whole thing....
im doing ab20 vtec and i dont have a vtec ECU.. but i have a vafc...
what do i exactly do to make it work... i kno i hook the vtec wire from the solenoid to the vafc vtec on... and ground the other wire to the block somewhere.. and what do i exactly do with the pressure switch wire? hook it up with the ground of the vtec solenoid?
ps. this is my crv b20vtec project.. its an auto .. and its hard to find the gsr auto ecu.. plus i would have to hook up a knock sensor
im doing ab20 vtec and i dont have a vtec ECU.. but i have a vafc...
what do i exactly do to make it work... i kno i hook the vtec wire from the solenoid to the vafc vtec on... and ground the other wire to the block somewhere.. and what do i exactly do with the pressure switch wire? hook it up with the ground of the vtec solenoid?
ps. this is my crv b20vtec project.. its an auto .. and its hard to find the gsr auto ecu.. plus i would have to hook up a knock sensor
10-08-2004, 01:59 AM
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Re: vtec oil pressure switch (VTECVillain)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECVillain »</TD></TR><TR><TD CLASS="quote">
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.</TD></TR></TABLE>
this didnt work for my car... i hooked up a wire from A4 to D6 at the ecu and after 5k rpm, i get codes 21 and 22 when before i did this i only got code 22. im still trying to fix my vtec problem, im thinking its an oil pressure problem.
The way to use the JDM VTEC solenoid with a USDM ECU or any ECU that looks for a VTEC pressure switch is to run the wire from D6 (VTEC Pressure Switch) and tap it into A4 (VTEC Solenoid). This connects the pressure switch and VTEC solenoid circuit together which fools the ECU so it won't throw a CEL.
The first setup that I wired this way was a friend's car (95 DX with 98 JDM B18C + JRSC). It has been running flawlessly for nearly 2 years and sees it's fair share of abuse. There have be no side effects from this that I have seen nor have I ever heard anyone else that has had problems.</TD></TR></TABLE>
this didnt work for my car... i hooked up a wire from A4 to D6 at the ecu and after 5k rpm, i get codes 21 and 22 when before i did this i only got code 22. im still trying to fix my vtec problem, im thinking its an oil pressure problem.
10-11-2004, 06:04 PM
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Re: vtec oil pressure switch (ViXoN Hatch94)
I believe we've finally solved this one!!! We've been struggling with the same issue. We have a 1996 H22A JDM swapped into a 93 Prelude with a P13 ECU. We swapped the fuel rail and the throttle body from the H23. This made plumbing and electrical connections simpler. I tried both the A4 to D6 jumper and simply connecting D6 to ground. The A4 to D6 jumper works until you engage the vtec a couple of times. Connecting D6 does not throw codes, but the vtec doesn't engage.
Now we realize that the ECU is looking for a normally closed (connected) path to ground on pin D6. When the vtec engages, the pressure switch opens the ground connection. To fake out the ECU you need to install a $3 SPDT low current relay switch. We used a NTE R70-5D1-12. This is a 1 amp, 12VDC, SPDT relay. Radio Shack also sells a low current relay that will probably work. It is important to use a low current (5A or less) relay. This will have high coil resistance (150 ohms or more), which will keep the ECU load on pin A4 low. You cannot use a generic black 20 Amp (4 pins) automotive relay! It does not have normally closed contacts and the coil resistance is too low.
Connect one of the (relay) coil pins to ground (I used the screw on the ECU). Connect the other (relay) coil lead to A4 (vtec pressure solenoid). Connect the (relay) common pin to ground, and the (relay) normally closed pin to D6. This will cause the D6 to be normally grounded, and open with vtec activation.
I can post a picture if you need one. Good Luck!
Now we realize that the ECU is looking for a normally closed (connected) path to ground on pin D6. When the vtec engages, the pressure switch opens the ground connection. To fake out the ECU you need to install a $3 SPDT low current relay switch. We used a NTE R70-5D1-12. This is a 1 amp, 12VDC, SPDT relay. Radio Shack also sells a low current relay that will probably work. It is important to use a low current (5A or less) relay. This will have high coil resistance (150 ohms or more), which will keep the ECU load on pin A4 low. You cannot use a generic black 20 Amp (4 pins) automotive relay! It does not have normally closed contacts and the coil resistance is too low.
Connect one of the (relay) coil pins to ground (I used the screw on the ECU). Connect the other (relay) coil lead to A4 (vtec pressure solenoid). Connect the (relay) common pin to ground, and the (relay) normally closed pin to D6. This will cause the D6 to be normally grounded, and open with vtec activation.
I can post a picture if you need one. Good Luck!