Official How To: Vaf To Maf Conversion

[Mr.Jason]

So far i have eliminated the ATX solenoid codes by wiring up VRIS solenoids to Shift a, b, c, and TCC.

As long as you do not have any of the ATX (D) (2) (L) (R) wires hooked up to +12v telling the ECU what gear you are in it will not bitch about the missing trans temp sensor or the missing input turbine sensor. It will not shift while driving... it just thinks its in neutral or park.

If you have (D) hooked to +12v the solenoids click when it shifts at specific speeds. But you then get another code for Input turbine sensor.


The next step is to try and do this more cleanly with a resistor network.

[MonoxideChild]

thats the kind of update i love hearing! step by step were getting closer to getting rid of that damn CEL!

[Mr.Jason]

Its my intention all along.

[Vitaliy]

subscribed.

[Mr.Jason]

So after a long drive in to work i have now a few lingering ATX codes

706 Trans range position circuit
710 Trans fluid temp circuit
715 Input turbine

I can fudge 710, maybe 715, and 706 i think i just need to set the trans in (L) gear

[ZE Power MX6]

Good work Jason, this is similar to what my friend and I did when we swap a TL-S 6spd in his Accord V6. We ended up making a black box with micro controller that drives a bunch a relays to trick the ECU.

[Mr.Jason]

Yes, i may have to do the black box later when all the proto-testing is done.

[WhiteDart]

That was about how far I got when I was trying to eliminate the ATX codes quite a while back. The turbine sensor was what stumped me because it needs to see some sort of wave input, like from a VR sensor. I believe it was supposed to monitor torque converter lockup, which is awful tough when you dont have one. My solution was to add the turbo and ignore the CEL.


I think i may actually know where my old relay board is in the garage. If I can find it tomorrow, ill give you the resistor value I was using for the trans temp.

[ZE Power MX6]

Yeah, sensor like that are usually the toughest task on eliminating CEL on a ATX ECU. You pretty much have to find out from a shop manual on what kinda wave it is looking for, and program a micro controller to output that wave form.

[ls-6]

Yes, i may have to do the black box later when all the proto-testing is done.

Hey if you get it working post up on hackaday Its disapointing not seeing these automotive type hacks very often.







Ever since the second day of my MAF swap I have been having serious misfire issues and little time and no money to sort it out I did the swap cause my original VAF seems to have died from a massive backfire through the intake so going back wasnt an option.

I spent weeks researching millenia specific misfire issues and redid all my splices to no avail.

It started imediatly after running my car out of fuel one day (enjoying the MAF conversion too much lol) as in it ran fine up til it died then ran like crap when I put gas in it.

So I figured potential debris in the fuel system so that all got checked out with no change.


So eventualy I was forced to consider that it might be an ignition issue, so new plugs did nothing and replacing the wires with another set did nothing (my old set was chaffed a bit in places from not fitting with the G4 well) and obviously it couldnt be the disty as I had replaced it not so long ago as a precautionary measure with a shiny new aftermarket one.



So yeah my nice $280 aftermarket distributors ignition module after just a few thousand miles had split its self perfectly in half resulting in erradic spark and shit mileage ( had to keep it over 3k to go anywhere) and my car is again running better than new with my original 135,000 mile distributor back in place

[WhiteDart]

Hell yeah. It seems that if the original disties have stuck around this long, they're never going to crap out. Im still on my original with 286k. Only replaced the internal o-rings after they started leaking oil about 3 years ago.

Oh yeah, im still on the boosted MAF setup.

[Mr.Jason]

EDIT: see my post below also about O2 heaters with resistors. It will work for the 96 with 97+ ECU.


1996 with a 97+ milly ecu to do the following

1. Go harvest 1x ECU plug at a wrecker or extract two pins with pigtail wire attached. (To extract pin you need tiny flat jewler screw driver and also need to release the pin lock on the bottom of the plug by prying it down)

2. Install pins in your ECU to pins 3C and 3G (See picture link below)

3.
p0141 R-Rear o2 heater----Pin 3C --> \
-------------------------------------->> 50ohm 40w-50w resistor --> Pin 4A (switched +12v) (3C and 3G both feed one side of the resistor)
p0147 L-Rear o2 heater----Pin 3G --> /

This will eliminate the O2 heater codes 141 and 147 by the ECU thinking the rear heaters are working.

All 4 O2's will still have heating working, but your ECU will not recognize when a rear O2 heater is bad.


Also as a note, you cant use a 96 milly ecu in a 97+ unless you connect 3C & 3E (the harness wire side not the ECU pin side) to Gnd or the rear O2's wont have heat. as there is no ground path.

http://img638.imageshack.us/img638/2207/obd2ecu.png

pins are as looking at the front of the ECU or the back side of the plug where the wire comes out of

[Mr.Jason]

http://img638.imageshack.us/img638/2207/obd2ecu.png

pins are as looking at the front of the ECU or the back side of the plug where the wire comes out of


Warning: I take no responsibility for any fried parts or ECU's you may cause by following my findings. My text drawings are done on a 40" screen @ 1360x768 resolution.

Pin locations picture is a few posts up

You will likely be needing pins with pigtail wire to do the following, so go harvest some OBD2 ECU plugs and do some RE-Pinning. You might as well snip an entire plug 2 from an ATX OBD2 and also grab any one of the other plugs for spare pins. Plug 2 has all the ATX pins


ATX codes
p0750 Shift Solenoid A---- Pin 2A -->2.2k 1/4watt resistor--> splice to Pin 4AN (PCM gnd)
p0755 Shift Solenoid B---- Pin 2B -->2.2k 1/4watt resistor --> splice to Pin 4AN (PCM gnd)
p0760 Shift Solenoid C---- Pin 2F -->2.2k 1/4watt resistor --> splice to Pin 4AN (PCM gnd)
p1743 TQ-Converter------ Pin 2C -->2.2k 1/4watt resistor --> splice to Pin 4AN (PCM gnd)

Trans range / Park Neutral codes. I used an omron H3Y-2 12vdc 0-60 second timer to do this set at about 3seconds, but i think you can do it with only a DPDT 12vdc relay. OK short explanation. Pin 1F must see gnd before ECU has power, so it is normally closed to GND, but opens when fuel pump triggers relay coil. Pin 2R must see +12v after 1F opens, so when fuel pump comes on it energizes the relay, opening 1AF and closing 2R to +12v telling ECU it is in (L) gear. The reason for Dual pole Dual Throw (DPDT) is because one relay is switching two different signals at once.

The ECU must see Park neutral at key on, then it must drop park neutral signal when any gear is selected to +12v. Just FYI i paid $10 shipped for the Omron timer on eBay from china.

P0705 related to code 706 below

P0706 Trans range-------- Pin 2R(Trans L) --> terminal 8 on H3y-2 timer
P0706 Trans range-------- Pin 4A (+12v switched) --> terminal 12 on H3y-2 timer

P0706 Trans range-------- Pin 4A (+12v switched) --> terminal 14 on H3y-2 timer
P0706 Trans range-------- Pin 1AF(fuel pump control(Gnd when FP on)) --> terminal 13 on H3y-2 timer

P0706 Trans range-------- Pin 1F(PNP) --> terminal 1 on H3y-2 timer
P0706 Trans range-------- Pin 4AN(GND) --> terminal 9 on H3y-2 timer

http://imageshack.us/photo/my-images...212vdc60s.jpg/



p0710 Trans Temp snsr---Pin 2O -->1.0k 1/4watt resistor --> Splice to Pin 3AB (sensor gnd) (You might get away with a 2.2k resistor here)
p0715 Input Turbine------Pin 2P --> splice to Pin 4AH (NE+) Tricking the ECU with the crank sensor which mimicks the input turbine
p0715 Input Turbine------Pin 2T --> splice to Pin 4AL (NE-)

Emission & O2 Codes
p0135 R-Front o2 heater---Pin 4E--> \
-------------------------------------->> 50ohm 40w-50w resistor --> Pin 4A (switched +12v) (4E and 4I both feed one side of the resistor)
p0155 L-Front o2 heater---Pin 4I --> /

p0141 R-Rear o2 heater----Pin 3C --> \
-------------------------------------->> 50ohm 40w-50w resistor --> Pin 4A (switched +12v) (3C and 3G both feed one side of the resistor)
p0147 L-Rear o2 heater----Pin 3G --> /

Faking the rear O2 sensor signal keeping codes eliminated and as a bonus setting the Cat readiness monitor. By adding this diode inline instead of simply putting the front O2 input direct drops the voltage by aprox half a volt while keeping an O2 sensor like signal. This allows the setting of CAT, EGR readiness monitors, but it still shows the Rear O2's as not ready. I am going to assume this has to do with decel cut should show both O2's at the same voltage rather than half a volt less. Or it could be looking for resistance fluctuations in the Rear O2 Heater circuit for temperature changes.

P0140 O2 (Bank 1 Sensor 2) ---3D--> (|< 1N4007 diode)-->3I (Note diode stripe lead connects to 3D)
p0140 O2 (Bank 1 Sensor 2) ---3H--> (|< 1N4007 diode)-->3M (Note diode stripe lead connects to 3H)

Note: I may not have the O2 code number matched with the correctly labeled R-Front or L-Front etc, but the pin number matches the L-Front / R-Front etc. You can use a resistor from 40-50 ohms with 40 to 50 watts. I will be buying 50ohm 50watt Tuesday if i can find them locally. You can string two 25ohm 25 watt in series to obtain 50ohm 50 watt.

Example:
Chassis mount : http://search.digikey.com/us/en/prod...0R0-ND/1646206

Thin or Thick Film: http://search.digikey.com/us/en/prod...0-F-ND/2138973


p0450 Fuel tank pressure(EVAP)---Pin 3A-->2.2k 1/4w Resistor-->--2.2K 1/4w Resistor-->Pin 3AB
p0450 Fuel tank pressure(EVAP)---Pin 3U-----------------------^ (Connects between the two series resistors)

p0450 Note* see this diagram for reference, just note the Pin 3A is 5v Vin reference, pin 3AB is the sensor ground, and 3U is the pressure input.
http://upload.wikimedia.org/wikipedi...ve_divider.png

p1455 Fuel tank level--pin 3K --> Connect to pin E (Yellow wire) of large white gauge cluster plug to input the fuel sender signal to the ECU.

p????? Canister Drain cut solenoid --pin 4R --> 2.2k 1/4watt resistor--> Pin 4A (+12v main relay) Note: 97+ ecu's show a vac solenoid valve relating to canister drain cut valve. While i did not encounter a code for this yet, it may be a problem for the readiness monitors so i am putting a resistor on it to be safe.

p1195 EGR boost---work in progress---install KL47 MAP + solenoid assembly wired in correctly. Plumbed the MAP to the cruise control nipple as i am testing this on OBD1. So far i dont have code 1195 after 100-150km of driving.

[ls-6]

I knew it was just a matter of time till these pinouts got put up this time next year I expect we will have a fairly complete set for maf swaps using any year millenia ecu into any 91-97 KL vehicle

Hell yeah. It seems that if the original disties have stuck around this long, they're never going to crap out. Im still on my original with 286k. Only replaced the internal o-rings after they started leaking oil about 3 years ago.

Oh yeah, im still on the boosted MAF setup.

Well for the 95 and newer ones anyway lol. Now that I know my MAF swap hasnt been my problem Im going to try some S injectors this week, then a rough assembly of my turbo system hopefully before the snow falls again and sticks for the next 4 months. I still need a way to connect the compressor outlet to the MAF and some sort of X member solution. I was going to go ghetto and use the original internal wg but after trying to make my PS headders fot my PS cat back and dealing with leaks and constant clunking I decided paying up for an external gate is well worth it if I can just bolt the kits DP to my exhaust:/ But all said and done I should be boosted for very little cash even if its been years in the making.

[Mr.Jason]

The O2 heater resistor mod for a 96 using a 97+ milly ecu should net more people using any ECU they want. Just dont go above year 2000 ECU's.

If you have headers and currently have O2 codes for the rear O2's you can try the 18mm spark plug anti fouler trick to eliminate the codes.


Just as a side note, i currently only have 3 codes 450, 1455, 1195. My evap, EGR, and O2 are not ready