Dash Mounted Exhaust Valve Switch

[Daemon42]

Quote, originally posted by MYGTIEA337 »

Im still confused on hoe the resistor ties in

Get a package of fuse taps from Radio Shack.. tap into fuse 34 as described above.
Run a wire from there to the resistor, and then from the other side of the resistor
to anywhere on the wire that goes to the ECU (either where you
originally cut it at the switch, but either way it's the up harness wire.

And note.. THIS DOES NOT REPLACE ANYTHING..
It is an additional wire. Don't cut anything to add it. Just T it off. Make sure that the
resistor is between the point you T and the 12v source however, or the ECU
will be very unhappy when it tries to pull the signal down to to ground.

BTW, for those who've only done the two position switch.. "always loud" and "always soft"
and have a hanging wire going to the ECU. Just hook this resistor to the end of that
wire, and then from the other side of the resistor to the 12v tap.

ian



Modified by Daemon42 at 12:02 AM 6-29-2004

[Jrok]

So....

The 'other side' of the vac. solenoid is wired to 12v and the ECU just pulls the line to ground to activate it ? The control line is directly connected to the ECU, no relays or anything in between ?

Hmm.. I want a wireless control switch ;-) Time to dig out some of those short range RF modules I never got around to using...

- James

[Daemon42]

Quote, originally posted by Jrok »

So.... The 'other side' of the vac. solenoid is wired to 12v and the ECU just pulls the line to ground to activate it ? The control line is directly connected to the ECU, no relays or anything in between ?

Correct. It might use a power mosfet or something in between but it also appears
to have the ability to test to see if the line has a load on it to protect itself from a dead short
and verify that it's there at all, so it may very well just be connected directly to the ECU.

ian

[encrypted]

Quote, originally posted by Jrok »

So.... The 'other side' of the vac. solenoid is wired to 12v and the ECU just pulls the line to ground to activate it ? The control line is directly connected to the ECU, no relays or anything in between ?

What Ian said, and for those who might care about the details...
- The 'test' seems to only occur on START (or immediately afterwards).
- The 'other side' of the solenoid is wired to some sort of switched +12V that is only 'hot' when key is in run/start positions.
- The solenoid pulls 400mA constantly (people have said that the pump turns off when the vacuum reaches a set level, but this end of the solenoid is not affected).
- The ECU actually pulls the solenoid control line to GND when key is in off/acc positions.



Modified by encrypted at 9:30 AM 6-29-2004

[schwordr]

Anyone going to Waterfest that has sucessfully completed this MOD?

If I dont have my operational by then, would you be willing to help trouble shoot it?

thanks

[maraude_r32]

Quote, originally posted by encrypted »

What Ian said, and for those who might care about the details... - The 'test' seems to only occur on START (or immediately afterwards). - The 'other side' of the solenoid is wired to some sort of switched +12V that is only 'hot' when key is in run/start positions. - The solenoid pulls 400mA constantly (people have said that the pump turns off when the vacuum reaches a set level, but this end of the solenoid is not affected). - The ECU actually pulls the solenoid control line to GND when key is in off/acc positions. Modified by encrypted at 9:30 AM 6-29-2004

So does this mean that if you start the car in the normal position and after … say a minute switch it to loud it will not throw a code? (trying to avoid using the resistor)

[gabedibble]

no, [without the resistor] whenever it's in loud mode, the computer throws a code

if you're worried about the code, put it in default mode before going to the dealer or just add the resistor and take care of it all

[JFNovae]

you are a pionere my friend. I would not dare do this on my own. I live in LA, CA and was wondering if you could send me to someone with the skill and confidence to do this job right. Please adise.

[NorthAtlR32]

Hey guys,

Bought an SPDT switch from Fry's Electronics. This one only has three terminals, instead of six - (DPDT has has six terminals). Costs $2.29 plus tax. The switch is manufactured by GC electrical and the number is 35-005. Product description is: On - Off - On Miniature Bat Handle Toggle.

Hope someone can use this if Fry's is closer than Radio Shack!

[Golfsyncro18T]

Has anyone figured out how to disable or change the operation of the solenoid using VAG-COM? Seems to me that it should be possible to change the speed/rpm activation point.

Modified by Golfsyncro18T at 4:49 AM 2-15-2009

[graeme86]

That would be programmed into the ECU software, so a smart tuner would be able to adjust it... if they knew where the code was.

[whitetrashrob13]

is this flap you speek of only on stock exhaust???

[RIP97vr6]

I thought I'd bump the original to add to the knowledge base.

At some point my 3 way flapper mod stopped working in "stock" mode. Last night i troubleshot the whole thing.

obvious stuff:
-Switch is fine
-Ground at switch is fine
-auxiliary +12V brought to switch is fine
-wire from solenoid shows 0 with acc off then +12v when on. therefore sol is getting it's proper +12.


If i short the up and down harness wire (bypassing all the switch stuff) the flapper is still open. This means my ECU is not pulling the solenoid to ground. It wont pull it regardless of rpm. I can also prove it with a meter as ground to up wire (grey wire up to ecu) never shorts from idle to 4K+ rpm.

So, there was talk about the up to ECU wire going through something else before the ecu. Any thoughts? I think its the only hope the board doesn't have a problem.

I have a UM NA tune, is it possible the flash has affected the stock flapper function?

[Yak Meat]

I hid mine:

[jmh2002]

At some point my 3 way flapper mod stopped working in "stock" mode. Last night i troubleshot the whole thing.

I have a UM NA tune, is it possible the flash has affected the stock flapper function?

Doesnt the UM Tune set the flapper open all the time? Im sure its been mentioned a lot in other threads.

[RIP97vr6]

Hm, yea, I just found a thread that states that. I searched yesterday but the terms "flapper UM Tune" come up together a lot.

well, i guess that's it. I'm not sure how i feel about that but that's off topic.

[jmh2002]

As far as I remember reading you can ask UM to have the flapper action set however you want.

[euro-mutt]

so with the UM tune the flapper can be set to always open? i had the tune done at h2o and wasnt there for that question if they ask it. i went to put the hose back on today and noticed there was no vacuum from the hose nor did i hear any change in the exhaust when i re-installed the hose. so this could be from the tune? id rather not go and chase a problem that isnt there

if this is true i have no reason for my flapper switch i just ordered

[P ARKUS]

With the UM tune, you can put in a switch to have the flapper either always open or always closed. What you lose is the stock function of the flapper opening at a certain RPM. Therefore buying the switch is not a complete waste. I've always ran with it perminently open, but i'll be putting a switch in just cause I love the reactions I get from people showing them the difference between open and closed