Air Pump Simulator DIY for $12.45
 

I have completed my final version of my air pump simulator and it passed the testing this morning with no error codes. All parts from Radio Shack and total cost $12.45. No more $150-$200 to buy these online. I will post the complete DIY this evening when I get home from work. Here's a picture of the unit:


http://i222.photobucket.com/albums/d...PunpDIY010.jpg

http://i222.photobucket.com/albums/d...PunpDIY006.jpg

wait, what? why are you removing your secondary air pump?
just curious...

Been removed for 1.5 years. Needed the room in my engine bay to hide my meth system where the pump was, it's heavy, no use for it when you don't have a cat converter. Track headers don't have the hook-up for the air pump either. Lots of reasons like the ugly piping going accross the front of the engine to the header, etc. I remove all items not needed in my setup. Weight reduction is free excelleration and everything adds up when you do a lot of small things.

The air pump only runs for 2-3 minutes during warm-up to help the cat reach operating temp sooner. That is it's only purpose and I bet it weights 10 pounds.

are you sure Nick G cant incorporate the elimination of the SAP into his software, as he does with the DISA valve?

also, how did you plug up the hole for the secondary shut off valve??

I'm sure Nick can do it but it is illegial to eliminate pollution control devises. Guess it depends on how good of a friend you are with him. DISA valve is not a pollution control devise it is a tuned intake manifold devise that is eliminated with a DASC. I removed everything (Pump, valves, etc) and plugged the hole from the header with a brass plug. When I install the metric motor I'm welding the hole on the header for the air pump and doing a header wrap to reduce heat.

Dude, chill out on the solder. Haha, use some flux next time and practice makes perfect!

Believe it or not I'm a expert at solding. Problem was I was not sober with very shaky hands when I did this. I normally use a air solder gun on pc boards but used a large tip trigger gun. I do hobby wiring on BGA (ball grid array) chips were there are 80 pin out's in the size of a dime, by hand. Also I had to add and remove pots, resistors, etc to get the correct resistance for the mv I needed. I couldn't use OHM's law because the O2 sensor is a voltage generator with no reading or data on watts or amps. If I did one today sober and a fresh board it would look sharp trust me. I would post some pictures of my hobby work but I don't want to expose who I am in the pirating world of smart cards.

John S

Air Pump Simulator DIY
 

DIY Secondary Air Pump Simulator.

Secondary Air Pump Parts Needed (All Purchased @ Radio Shack):

1 - Component PC board (#276-149 $1.99)
1 - Component Project Enclosure (#270-1802 $2.69)
1 - SPDT * PC relay miniature 12vdc 10V (#275-248 $4.69)
1 – 5V Voltage regulator (# 276-1770 $1.59)
1 - 100K – ohm Micro Potentiometer (#271-284 $1.49)

Tools Needed:

Soldering pen 7 watts or higher
Solder
Wire
Digital volt meter


Place relay, potentiometer and regulator on board as shown in picture. Solder all pins on back side of board. Go to wiring diagram and make connections. When finished test unit by hooking to 12 volts and set potentiometer with a screwdriver to 200mv from pin DME wire to ground. Potentiometer should be between 45,000 and 50,000 ohms if you want to ohm it out. Questions to jsmith50@tampabay.rr.com

***This is for off road use only***
***I accept no responsibility for items burned out or damaged by mis-use of this devise. The DME & O2 are sensitive devises and can be destroyed by sending the wrong voltage to the units***

Top Of Board

http://i222.photobucket.com/albums/d...TopofBoard.jpg


Bottom of Board

http://i222.photobucket.com/albums/d...ackofboard.jpg


Wiring


http://i222.photobucket.com/albums/d...Spoon-Feed.jpg

wtf i was trying to look for my SAP and i didnt find anything can someone tell me where is located (m44 engine)

Should be left side under the hose from the air filter. It's mounted on the strut just above the frame. PM sent back...

well i guess i dont have one, weird

some pics :eek:

I think the secondary air pump was added in 1997.
Your being a 1996 doesn't have it.

mine is 5/96 production date

Yea, I saw that and edited. It was 1997 then (or heck, maybe even 1998), but for sure the 1996 didn't come with one

okay thanks for the info

I'm seriously thinking about doing this as the way Dawning Atlanta designed the relocation of the SAP it's a PITA... The alternative to the simulator is a small cone filter... Routing that 1" hose all the way up front looks a piss poor job...

Give this will bypass the SAP, how would you bypass the solenoid controlling the vacuum line going the check valve? Would that need to be simulated as well or it's a non self diagnosed part?

Ok. I've purchased all the parts at RadioShack for $13. Now I'm trying to determine where the DME and O2 sensor wires come from. The other 2 wires will probably be obvious. I think I'll return the black plastic box and find another way to secure/protect the board. the board doesn't fit in the box correctly.

hope this help
http://deluxenailnspa.com/s2000/IMG_0091.jpg
http://deluxenailnspa.com/s2000/IMG_0092.jpg
http://deluxenailnspa.com/s2000/IMG_0093.jpg
http://deluxenailnspa.com/s2000/IMG_0094.jpg

the board does need to be sand down a little bit in order to fit in the box

yellow=ground
green=positive
red=dme
blue=o2

is this right?
 

xxxJohnBoyxxx can you check my work please, this is my first time making this secondary air pump simulator i want to make sure it is right before i go further.

also the plug that i unplug from the bottom of the sap is the power and ground, but where do i connect the dme and o2 wires to?

thank you.

When you install the simulator, do you leave the pump installed? What is the reccomended places to tap in the wires? I know the + &- must go the the plug in the bottom of the old motor, but where will the othetr two (DME and O2) connect? Should I locate the wire and tap into it?

Everything looks good. I can't ensure the voltage regulator is in correct by the picture. Looks like you turned it upside-down and wired correctly.

Move to test stage:

1. First test continuity (Meter set to ohms) between DME and O2 wire with no voltage to unit and you should have a dead short. You are ensuring DME and O2 are connected together in the relay when there is no power. If good move to step 2

2. Apply voltage to simulator and listen for relay to click on. With simlator on test voltage positive lead on DME wire and Negative on battery ground. You should see 200mv or .200 volts or close to that. If not adjust the pot resistor to get 200mv or .2 volts on your meter when the unit is active. When completed disconnect power and the unit is tested and calibrated....Ready for install.


+/- connection: SAP positive to Simulator positive so it becomes active only when the SAP is called for by the DME. Negative to any good ground or SAP ground (Your choice ~ Ground is ground)

O2/DME connection: We are only looking for one wire to connect to. The upstream O2 signal...On my car 1997 BMW 318is the O2 signal is grey then goes to the plug and changes to a yellow on the way to the DME. This signal wire is the one we want to tap. You can tap Grey on the O2 or Yellow after the sensor plug which is still the O2 signal wire on it's way to the DME. Cut the signal wire and wire simulator wires O2 to O2 sensor and DME to the wire leading to the DME.

What we are doing here is only putting the simulator in line with that O2 signal wire to fool the DME when the SAP comes on.

Therory ~

When the DME calls for "SAP On" then it expects to see a lean condition on the upstream O2 sensor. If it doesn't see the lean condition from the SAP forcing fresh air in the exhaust it throws a CEL code. This is the only check for the SAP

SAP On ~ Simulator active. The simulator disconnects the O2 sensor from the DME and sends a false 200mv signal to the DME telling it the exhaust gas is very lean. The DME is "happy" since it expects this signal with the SAP on so no CEL or error codes.

SAP Off ~ Simulator off. DME calls for "SAP Off". The simulator when in a off state: When in the off state the relay is used as a pass through for the O2 signal wire so the O2 is connected like the wire was never cut. Car runs like normal and full Lambda conrtrol is active and car runs normal like nothing was ever changed.

Your choice on the SAP. I remove it for the extra space and weight removal. Wiring is in post above.

Questions on wiring not explained above or too confusing call me

home: 727 321-0460
cell: 305 742-8559

Eastern Time Zone, Name is John

if you could clear this up for me a little, i have two wires i need to connect on the simulator the DME wire and the O2 wire, the wires that i need to tap into are somewhere near the sap? where do i find these? you say one wire to connect to? i am not clear on this.

thanks.

Yes we cut one wire, the signal wire from the upstream O2 sensor. The cut wire has two ends now. The end leading to the O2 gets connected to the O2 from simulator. The other end that leads to the DME gets connected to the DME wire from the simulator. We are only patching the simulator into one wire of the O2 sensor (the signal wire). When the SIM is off it connects the cut wire so the O2 operates normally like the wire was never cut. When the SIM turns on it disconnects the O2 and sends a false signal (200mv) to the DME to fool it into thinking the SAP is working. Call me at home if not clear, it is so much easier to explain over the phone, I don't mind calls at all. Best John S

Do you think this device would work on a 323 with a 6cylinder M52 OBDII engine? The six has two front O2 Sensors.

Yes but you need to make the I-6 version (Dual Bank). I think there is a DIY on that too or at least I posted one with pictures...

Where can I find the DIY for the dual bank version? I tried using Google, and the only one I have found is the one for the M44. Thanks

I would just make 2 simulators: one per O2 sensor and call it a day. There's enough room on the board to make them fit them in a single box, already sharing ground and 12V inside the box. You'll end up with 6 wires instead of 4: 1 for ground, one for 12v, 2 for O2 (one per sensor) and 2 for DME (one per sensor)...

I have a DIY for this I'm sure because it was used in the I-4 to I-6 swap manual. It is on this board. If not I will email it too you. Ipcapitol is correct you just make two on one board, the only shared item is the regulator


Edit ~ It's right here ~ http://www.318ti.org/forum/showthread.php?t=24726

Thanks very much. I do appreciate your help. Doug

my o2 sensor plug has a black wire, grey wire and two white wires, then at the plug they turn into the following:


black goes to yellow
grey goes to black
white goes to green
white goes to brown

on a 1999 318TI

i read the following on pelican article:

Lastly, with a 4-wire oxygen sensor, the output signal works in a constant loop, essentially, the fuel injection computer sends a signal to the sensor, and the sensor then sends the signal back to the computer. This is achieved by having one wire carry the signal to the sensor, and then another wire carries the signal back to the fuel injection computer. You also have a wire carrying 12 volts to the heating element, and the last wire is the ground for the heating element. (pic o2_sensor_diagram_4 jpg) With a 4-wire sensor, you will need to measure the voltage fluctuations between the two signal wires. To do this, start the car and let it warm up. Next, disconnect the oxygen sensor and measure the voltage between the wires. Now take off the oil filler cap to simulate a rich running condition. Watch the voltage, if it begins to fluctuate rapidly, then the sensor is good and you’re done. If it stays the same, it’s probably fried.

The two whites are heater wires the black is ground and the grey is signal. The O2 sensor is a voltage generator. It gererates voltage by the amount of oxygen in the exhaust. At least that is how I undersand them to work and how my simulator works.

If not how could the voltage fluctuate or be present at all if it is disconnected from the harness? Also running a O2 sensor in the exhaust stream without the heater wiries connected is a great way to burn it out real fast, just an FYI.

After speaking with you on the phone I think you have a wire mis-labeled.

O2 sensor wires to tap into O2
White = Heater
White = Heater
Grey = Signal
Black = Ground

After plug O2 wiring to DME cross-over wiring to tap into DME wiring:
Black = Ground pin 46 DME
Yellow = Signal pin 19 DME
Brown = O2 Heater Ground pin 30 DME
Green = Connects to all red/white wiring 12 volts in ignition on key position

SAP Simulator
 

So i installed my secondary air pump simulator in the car finally a few weeks back, i checked the simulator with multimeter for correct settings, wired it in correctly with help from johnboy here, i dont get any codes for o2 sensors and car runs great as usual, so i know its wired in properly, however i still get the check engine light on at right about 40 miles after scan and reset, whcih is how many miles have to be driven for the SAP system to be ready in the computer, in my 318ti. Its the only code in the ECU and i have reset it three times, same thing every time, at about 40 miles driven after scan code comes back, any ideas?

Sap Simulator need to put out voltage of 200mv on red wire to DME when the SAP is active. I think your mv is too high so the DME thinks the SAP is not working. It is very picky and needs to be set at 200mv. Are you sure the SAP is active when you first start the car. It should only run for 30-50 seconds then turn off. If the unit is not working the code should not show until the next time you have a cold start. Nothing about 40 miles into a drive, I've driven 250 miles with no code then the next cold start gave the code when the unit was not working...

I know of at least 25 units with no issues.

as for the 40 miles the ecu doesnt have the sap ready untill 40 miles after the last code reset, i dont know why this is, but this is why they tell you that if you recently had your cars codes deleted, you need to drive for a while before you take it into emmissions otherwise emmissions computer will tell you that your systems onboard are not ready, this is true because this is my problem, anyway i guess my only option is to try and check the mv readings on my module agian. By the way the check engine light would be triggered and is triggerred on the next cold start, the only difference is that it wont if i just deleted the codes, untill the sap system becomes ready in the computer, (40 miles driven after deleted SAP code on my car) only then is the computer able to check it. Will update after i recheck my module. thanks.

once agian i want to say thanks to johnboy for helping me, i figured out it was the voltage regulator that was no good, i rebuilt the simulator and realized the old voltage regulator was not putting out the 5 volts as required. Will be deleteing SAP check engine light code again and will test drive and see what happens.

UPDATE:
 

well after remaking the simulator with a working 5 volt regulator, i realized that the simulator is still not turning on (it does turn on when connected directly to the battery instead of using the old SAP wires) (i installed a red led to be able to see too), so got out the multimeter again and went fishing, found that the original GROUND wire going to the SAP was not grounding the whole time!

I moved it to another place and simulator is now functioning, well see how it goes after driving the car for a while.

By the way, if I made the simulator again i would do the following in addition to installing a 12volt LED on the positive lead for SAP, i would also install a different color led on the 5 volt regulator to make sure its working and if possible another color led to show either that the simulator is feeding data to the ecu or that it is off, therefore sending data directly from o2 sensor to ecu.

And better yet install all three leds inside the car next to the ASC-T switch, so i can see it inside, instead of having someone else look under the hood, or me getting out of the car to check. But now im just getting fancy!

So I got all the parts for this mod (and extras because I suck at glueing stuff together) and my BMW buddy asked me if we could do it for his V8 as well. I know the v6 needs the dual bank version, would the v8 need 3 banks?

Thanks in advance. Sorry I forgot to ask him what series this is for.

Where do I locate the DME and O2 sensor from the car to connect the Grey DME wire and Blue O2 sensor wire?
Do you have pictures to show how the wires are connected from the built simulator to the car DME and O2 unit?