45 replies to this topic

[Ipd]

*THIS IS FOR TRACK CARS OR DEDICATED NON ROAD GOING VEHICLES, ANY TAMPERING WITH FACTORY EMISSIONS SYSTEMS IS A VIOLATION OF FEDERAL AND STATE LAWS*

That being said...

With this method you must keep the SAS pump relay connected as well as the SAS check valve solenoid connected, otherwise all SAS parts can be removed.
This method is for 98 cars, have not yet confirmed for 850 models.

Brief explanation of how the ECU monitors SAS and determines if it is working.
The ECU monitors the SAS function on three fronts
1. Looks for 12v coming through the SAS pump relay coil before it grounds it. If disconnected the ECU will set CEL for open circuit.
2. Looks for 12v coming through the SAS solenoid coil. If disconnected the ECU will set CEL for open circuit.
3. Looks for low voltage coming from front O2 sensor signal when SAS is active

Supplies:
Diode with ~1.6v drop across it, Try a radio shack #1N4003 or similar rectifying diode. Recall that a diode is essentially just a check valve for electricity, allows current to flow one direction but not the other.

The diode must be connected between the SAS relay ground control pin and the front O2 sensor input pin.
The diode must be connected so that ground from connector B pin 38 on the ECU can flow to connector A pin 32 but not allow the 12v from connector B pin 38 to flow into connector A pin 32.

This can be done either on the wiring harness or simply inside the ECU and bridge the internal pins, I prefer the latter method as the wiring can then be left stock and the ECU changed if for some reason you want to go back to original setup.

That's it. I'll confirm this further for M4.3 cars in the near future.
Thanks - Comments welcome

[Mahi]

The diode must be connected so that ground from connector B pin 38 on the ECU can flow to connector A pin 32 but not allow the 12v from connector B pin 38 to flow into connector A pin 32.

You mean that pin A-32 can flow through to pin B-38, but not vice versa?

I haven't tore open my spare M4.4 ECU to check but what does the circuitry around pin B-38 look like? I'm wondering that over time the controlling transistor (BJT or MOSFET) may not like having that extra voltage/current flowing into it. Also, how much current is flowing through the diode? It be prudent to add a resistor in-series with the diode keep it from dumping an unnecessary amount of current into the other pin without compromising the functionality of the modification.

[Ipd]

You mean that pin A-32 can flow through to pin B-38, but not vice versa?

Correct

Also, how much current is flowing through the diode? It be prudent to add a resistor in-series with the diode keep it from dumping an unnecessary amount of current into the other pin without compromising the functionality of the modification.

minimal current, whatever the O2 sensor is flowing which is in the neighborhood of a few milliamps

[flaco]

Supplies:
Diode with ~1.6v drop across it, Try a radio shack #1N4003 or similar rectifying diode. Recall that a diode is essentially just a check valve for electricity, allows current to flow one direction but not the other.

Sounds like a great idea! Wonder how you came up with the 1.6V drop figure? Most normal rectifier diodes (1n4003 included) have only a drop of ~0.450V. This mod will effectively cap the voltage from the o2 sensor to 0.450V.

That is a perfect signal to indicate 'lean' from the front sensor btw.

btw if anyone is interested in doing this mod but feel afraid of hacking the ecu, I could do it for you. Just pay shipping and a couple bucks for the diode and a 6-pack lol...

[98 s70 t5m]

So simple! nice work. I wish this hade come up 6 mos ago as I went thru all the trouble to plumb my SAS in to avoid CELS.

[POSTITSORGTFO]

Sounds like a great idea! Wonder how you came up with the 1.6V drop figure? Most normal rectifier diodes (1n4003 included) have only a drop of ~0.450V. This mod will effectively cap the voltage from the o2 sensor to 0.450V.

That is a perfect signal to indicate 'lean' from the front sensor btw.

btw if anyone is interested in doing this mod but feel afraid of hacking the ecu, I could do it for you. Just pay shipping and a couple bucks for the diode and a 6-pack lol...

Helloooooooooooooo there how about a case of what ever ?

[flaco]

Helloooooooooooooo there how about a case of what ever ?

OOPS, forgot you were planning to charge for this LOL

[lookforjoe]

Nice!

Much simpler than the POT setup.

How long have you tested this for? The other method can take a month or more to set a code if the POT isn't quite right.....

[303jrodt5]

I followed Husseins awesome write up and still cannot get my CEL to stay off for more than a week. I have dialed the POT in to numerous different voltages and cannot get it to work. Maybe I will put that back to normal and try this.

[mkc70]

Sounds like a great idea! Wonder how you came up with the 1.6V drop figure? Most normal rectifier diodes (1n4003 included) have only a drop of ~0.450V. This mod will effectively cap the voltage from the o2 sensor to 0.450V.

That is a perfect signal to indicate 'lean' from the front sensor btw.

btw if anyone is interested in doing this mod but feel afraid of hacking the ecu, I could do it for you. Just pay shipping and a couple bucks for the diode and a 6-pack lol...

Good offer, but isn't that diode priced in the pennies(excluding Radio Shack inflated prices)?

[revolvolution09]

Hmm i def wanna get rid of sas.

[flaco]

Good offer, but isn't that diode priced in the pennies(excluding Radio Shack inflated prices)?

Yep, I'd prob get them from mouser, ~10c each. Then a 6-pack is what? $5?

[mkc70]

Yep, I'd prob get them from mouser, ~10c each. Then a 6-pack is what? $5?

I guess that depends on the brand of the 6-pack.

[Keep Calm Chive On]

man i gotta learn bout electronics cause i would love to take my SAS pump into a field with a bat an smash it somewhat similar to office space and the paper jam printer. "PC load letter? what the poke is PC load letter"

perhaps someone local to binghamton or someone going to carlisle would love to help me do this? ill pay for the parts an alcohol needed. (i dont like electricity of the idea of me funking up my ride) and you can even keep my working SAS pump for free.99

[C_M_MARSHALL]

I'm going to try this method on the V70.

Currently on the C70, I am running lookforjoe's setup and I am in the process of dialing in the POT. I set it according to the instructions but I still throw a code every 3 - 4 days. Every time I clear the code, I turn the POT 1 half turn increasing the resistance....Ive been doing this for the past week. Eventually I hope to get it just right so the code doesn't come back....than I will remove the SAS hardware and plug the system up.

[Commander Riker]

Great writeup lucky. We've tried the pot method on scandalo's car without success.

This would be a cool thing to do as a group at the carlisle convention. I cannot think of a more delightful image right now than a pile of our SAS pumps/valves in a trash can.

EDIT: (Someone please sticky this)

[SKI-R]

PC with VADIS on it has died......

Before I go scrabbling around to sort out which pin represents which wire......... do I correctly interpret this to be that the diode would go into the SAS ground relay wire? And if so (or not), can anyone tell me the wire color off the top of their head?

This thread just bumped Hussein's from my bookmarks!!! Thanks Lucky.

[Keep Calm Chive On]

so if i were to get a 10 or whatever pack they make the diode in perhaps like stated above we could have a SAS deleting party? then take all the SAS pumps and do something along the lines of Office Space & smash them with bats? Ill bring a CD with "Still - Geto Boyz" just in case.

I really ask because i know nothing in regards to electronics and i would rather have someone that has either attempted or done this before i take a crack at it.

[GltGreco]

Would love to do this so i dont have to have a bung welded for my exhaust, wish i knew more about electronics in this sense. If anyone local to me (ri) knows how to do this ill thow you a little cash or something if you wanna take a crack at it for me/with me.

[fischmama]

If anybody wants me to do it at Carlisle, I can. I may do mine as well then (using the Lookforjoe method right now). Just as a reminder I will not be responsible for any damage/not working stuff.&nbsp;<div><br></div><div>Let me know and I'll bring my soldering iron.</div>