Air Pump Simulator for 2 Bank all 6 Cylinders
 

I have created a air pump simulator for all 6 cylinder BMW engines with 2 upstream O2 sensors. It is the same size as the M44 unit but controls both bank 1 & 2 for a 6 cylinder engine. I'm shipping one off today for testing and will post pictures and wiring diagrams when I get some time later this week. Just an FYI.

***This is to be used for test purposes or on track cars only***

http://i222.photobucket.com/albums/d...6cylinde-3.jpg


http://i222.photobucket.com/albums/d...cylinders0.jpg

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

DIY Secondary Air Pump Simulator. 2 Bank all 6 cylinder BMW

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)
2 - SPDT * PC relay miniature 12vdc 10V (#275-248 $9.38)
1 – 5V Voltage regulator (# 276-1770 $1.59)
2 - 100K – ohm Micro Potentiometer (#271-284 $2.98)

Tools Needed:

Soldering pen 7 watts or higher
Solder
Wire
Digital volt meter


Place both relay, potentiometers 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 potentiometers with a screwdriver to 200mv from pin DME wire to ground. Potentiometers 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***

I recently added the air pump simulator to my 97 TI with an S52 motor and it works great. I created a PCB layout for me and anyone else who would like to use it. I got all the parts from radio shack and etched the board. Pin 1 in the circuit below is the square pin on the board. If you do not feel like making a board I uploaded the board files to batchpcb so you can buy one pre made for fairly cheap. http://batchpcb.com/index.php/Products/53138

The PCB can also be used for the 4 cyl engines, just don't populate a relay and a potentiometer.

Here is the parts list that I used from Radio Shack:
1 - 7805 +5VDC Voltage Regulator (#276-1770 $1.59)
2 - 100K – ohm Micro Potentiometer (#271-284 $2.98)
2 - SPDT Mirco Relay 12VDC (#275-0241 $9.38)
1 - Project Box 3x2x1 (#270-1801 $2.49)


https://lh5.googleusercontent.com/_t...209_204050.jpg

https://lh4.googleusercontent.com/_t...209_211047.jpg

Attachment 10998

Attachment 10999 Attachment 11000 Attachment 10997

***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***

how have these simulators been doing since installation? any CEL issues. bluesteel, i really like the board you had designed. i'm thinking about buying a few & building some for my friends & I.

No issues on the single simulator that I've run and many others for over two years no issues reported on the dual bank since they have been in service.

John S

Secondary Air Pump Simulator
 

will the Secondary Air Pump Simulator work on a 2003 Z4, 2.5, 5speed?
Thanks

love this DIY!

where do you connect the wires to?

Air pump positive and negative to activate the simulator, then you clip the signal to your O2 sensors and patch the other simulator wires in. When the simulator is off it is a pass-through like you never cut the signal line. When the DME calls for air pump the simulator goes active and cuts O2 signal and sends a 200mv signal to the DME fooling it into thinking there is additional fresh air in the exhaust from the air pump system working.

Best, John Smith

Bringing this thread back from the almost-dead: why would you build a 6-cyl/double O2 sensor) version with two SPST relays instead of one DPDT?

Neil

My original simulator was for the I-4 motor and then I was asked to make one for the I-6 so I made it with extra parts I had for the I-4. Please feel free to make your version I-6 with the DPDT and post the schamatic.

Oh also you need to check to ensure Radio Shack sells the DPDT. IDK since I never looked for one in my local store. People like all parts in one location.

John S

Good point - RS doesn't offer a DPDT micro relay.

The Omron G5V-2-H-DC12 ought to do nicely, Digikey P/N Z771-ND for $3.22 each. See http://search.digikey.com/scripts/Dk...l&name=Z771-ND.

Adapting it to your reference circuit is then trivial.

Neil

Do a digikey parts list for the forum. These can be made for much less but I was doing with local parts that anyone can purchase right away the day they want to do it. You could do one for half the price on-line which some people might want to do.

Someone needs to start making these. I get requests all the time but turn them down due to the time involved. I get emails weekly concerning these simulators for all kinds of cars and they work on anything with an air-pump. They can be adapted to wide-band with a little tweak of the voltage sent to the DME or ECM. Also you can use resistors instead or pots but I like the pots incase you get a car that need a voltage tweak to get the computer happy.

Best, John S

Digikey

a) +5VDC Voltage Regulator (P/N LM7805CT-ND, $0.65)
http://search.digikey.com/scripts/Dk...me=LM7805CT-ND

b) 100K-ohm Micro Trimmer Potentiometer (P/N 987-1060-ND, $2.02)
http://search.digikey.com/scripts/Dk...me=987-1060-ND

c) DPDT Micro Relay 12VDC (P/N Z768-ND, $3.00)
http://search.digikey.com/scripts/Dk...l&name=Z771-ND

Notes:
- I picked components that are higher in spec, especially operating temperature range.
- The DPDT relay handles dual O2 sensor applications, but it's so cheap you could just not use the second pole for single sensor applications (e.g. 4-cyl).
- Although Digikey's mail order prices are much lower than Radio Shack's store prices, you may run into minimum order and service charge adders, an then there's shipping cost.

I think you're better off to pick up a project box and breadboard at RS.

Radio Shack

1 - Project Box 3x2x1 (#270-1801 $2.49)

Yeah, not me either!

Neil

John,

I have built this simulator for an E36 M3 and am having a couple of issues. I was hoping you might have some insight. I made the dual version for both my oxygen sensors. I wired it into my front two oxygen sensors (pre cat). Are these the correct sensors?

In addition, it seems to work fine during warm up unless I "get on it" a little. I am not saying beating it but if I am slightly aggressive, it will set the cel. Now if I grandpa driver it, no cel. Any thoughts on this?

I set the reference voltage to .2v and everything seemed to work for 2 cool days driving like a grandpa but on the third after goosing it a little, it threw the cel. Thoughts?

needs to be on the post cats!
pre cat O2's help balance the air/fuel ratio by measuring how much un-burned fuel is in the exhaust gas.

dantesboyz,

Have you installed one of these on your car?

Wrong this will not work. The DME reads upsteam O2's for SAP verification. The DME looks for a lean condition when the SAP is on since it's pumping fresh air in the exhaust. This is the whole reason this simulator works...It fools the DME into thinking the SAP pump is working on the front O2's. This works on all cars with a SAP.

The until only turns on during SAP. When SAP is off the simulator goes into pass-through mode and all your O2 reading or Air/Fuel ratios pass right through the Simulator to the DME untouched by the simulator. Look at the design and you will figure it out if you know anything about electronics

Hope this clears it up. I think there are at least 50 on these on cars with no errors. INSTALL on upstream O2's or suffer an SAP error...

John Smith

Hello Thanks so much for making this DIY
I would also like to know if this will work on a 03 bmw z4 2.5i and will it pass emissions?

As Im Having secondary air pump CEL as well

Yes it will work. The design is not for passing emissions however it will 100% of the time. The simulator sends the SAP operation checks to the DME and it can't tell if the pump is not working or removed

John - I am trying to install a 96 M44 into a 98 318ti and I am having trouble dealing with all the smog stuff in the 98 harness and such. I do not have the headers with the exhaust valve and I don't have the air pump. I was thinking that this simulator would solve most of my problems, but I still have other questions as well. Could you email me so I have a way of contacting you? Thanks!

I want it for M44, what's the difference, if any? Thanks!

Look up single bank simulator in the knowledge base.The M44 one uses the same therory but only one relay and one pot.

I just want to give a heads up that these parts are not compatible with the pcb board made by bluesteel.

they do not fit properly. therefore it's better to use the parts he suggests.

I made that mistake.

Single pot schematic
 

Since no one had a circuit diagram/schematic, I drew one up.

http://img.photobucket.com/albums/v3...umpsim-001.jpg

I gathered everything on Neil's shopping list, but I haven't assembled it yet.
If anyone does, take some pics and post them up. I'll do the same.

Thanks for this! would you say the signal has to be set to 200mv for all cars or do you think it could vary?

Im doing this for a z4. also I don't see any tutorials for my car and have no idea how to locate those cables.

I used all data which contains same as http://wds.spaghetticoder.org/ it explains how the circuit functions and the cables to look for. But the schematic only shows one cable going from the dme to the o2 sensors.


here is mine

http://img268.imageshack.us/img268/6724/pcbr.jpg

Is anyone willing to make me one of these for an m44? I suck at soldering and reading wiring diagnostics. I am willing to pay you for your time too!

I can make a 6 cilinder version..if you don't mind the extra cables.

or 4 I guess it's same thing

The 200mv signal is simulating a lean condition to the DME (computer) as reported by the O2 sensor. It is most likely the same for all cars.

You only need to identify the wires that run from each of your pre-cat O2 sensors to your DME. (one wire for each O2 sensor.) I'll see if I can find a link to your electrical schematics when I get home. E85 or E89?

If an electrical schematic isn't available, you can just find the pre-cat 02 sensors in your car, then identify the wires leaving them by color. My personal preference is to locate the sim in the compartment with the DME to keep it out of the elements. To do that, you want to locate and cut the two O2 wires to the DME a few inches from the connector to the DME. Bring the existing secondary air pump wiring back into that compartment as well.

Got it

E85 bmw z4 2.5 03 feb





I was thinking of leaving the sim at the pump but that makes more sense.

since everything gets to the DME anyway.


EDIT I created a thread since I feel my setup is slightly different

http://www.318ti.org/forum/showthrea...016#post318016

I built some SAP sims for 6cyl cars but they can be used on the 4cyl as well.

They is very high quality, not so "home-built" looking like the DIY version out there.

-includes everything necessary for installation (wire ties, butt connectors)
-electronics sealed in epoxy for protection against moisture/vibration
-high-temperature, color-coded GXL wire cut to correct length and covered in wire loom
-individually tested

Includes zip ties, butt connectors, and detailed instructions. $95 shipped, please PM me.

http://obsolution.net/bfc/IMG_2491.jpg

I just built one with a DPDT relay as spec'd out by DaveAZ here and it works great! Took a couple hours to solder it all together, then maybe 1 hour to route wires and place inside the engine bay. Cost all together about $15.

Thanks xxxJohnBoyxxx and DaveAZ for the inspiration!

Take a gander at the datasheet. Like many with its form, the pins are numbered as if you might plug it into a 16 pin DIP socket – for the good reason that some do. ;) BTW, that should be a good choice of relay for a car as its coil is rated to 180% of nominal voltage (12V x 1.8 = 21.6V) at 23 deg C.

The connections look o.k., but if you have any doubts, I'd print out the layout and schematic and double check them against the datasheet, marking off each signal with a colored pencil as you go. Or by the correctness of the relay wiring, are there other things you are wondering about?

Is there anyway to make this simulator work on e46 03/2003-2005 sensors?

http://www.oembimmerparts.com/v/vspf...34-35E46-2.jpg

It has a 6 pin connector and 5 wires. (red, white, yellow, black, gray)


And the simulator, does it have to be exactly 200 mv or can it be +-2 mv?

o2 Signal wire on '96 328i color verification
 

I built a SAP sim according to this schematic http://www.318ti.org/forum/showpost....9&postcount=25 except that I wired the pot with the wiper arm (middle wire) as the 200 mV source. The pictorial/schematic did not make sense to me otherwise with the pot as a voltage divider.
According to my Haynes manual, the forward o2 sensor wire connectors plug into the wires to the dme along side the fuel rails. The wire colors are red, yellow, black, and white. Readings there with a Fluke 77 dvm referenced to the chassis ground nut by the SAP were unstable, so I used the ground side of the SAP connector. The yellow wire was the one that varied between 0-1v., gradually increasing as the engine warmed up, so I clipped both yellow wires and inserted the simulator there.
Can anyone with a '96 328i verify that this is the correct wire? I ask because after resetting CEL it came back a couple of times, though it didn't this morning. Wife left in it this morning and it was running fine but can't tell yet because we're still having problems with a P0340 CPS error and I can't check 'til she gets back.

No SAP code again this morning (1-1-13). So it was the YELLOW wire that was o2 signal FYI.:smile:

The picture is a wideband O2 sensor. You can trick these too but need a 2.0volt simulator signal since wideband operates on a 0-5 volt range.

The narrowband O2 operates on a 0-1 volt range that is why 200mv is used to fool the DME.

I hope this is a dumb question, but will this 2 bank setup work equally well on the M5? I have read through the post and it seems as though it would, but I didn't see anybody that has tried it yet.
Thanks, and thank you for posting this amazing "test" for troubleshooting the SAP system...

I will answer my own question...yes it does! Just passed NYS inspection running this setup. Thanks so much, this was a lifesaver.