This is really great. Thanks for this post !!

 

Thanks great stuff. Would you recommend the USB or the serial port type for Windows?

 

If you have an very old computer with only serial you can use that, otherwise USB is the way to go.

 

Do you know if parameters can be adjusted that would reduce the sensitivity of the rear O2 sensor to help eliminate the dreaded and very common P0420 code ?

I would pay to have that ability.

 

Yeah Seabass I looked through the site and found there was only support for mostly turbo models.
I did see an open ticket someone requested support for a 2004 Outback NA AT.
Under ECU and Logger Definitions.



I believe I found a solution for this issue, now lets see that $. :12:
/joke

Assuming those with this P0420 code have eliminated all causes of exhaust leaking or air entering upstream of the sensor via holes or other damages to the components.
As well as a properly functioning catalytic converter.
There is an option to alleviate the P0420 code.
I have found a simple way to attenuate the signal for the rear O2 sensor.

Now I need to order up some parts and create an air leak in my exhaust to test it out.
The start of another fun and simple project.

Edit that: Someone already did the testing, good job TrekLawler.
Great I can leave my exhaust in 1 piece.
http://www.subaruoutback.org/forums/110-gen-2-2000-2004/27380-header-install-4.html
TrakLawler also put up the extremely complicated wiring diagram for this.

~$4 in Parts
1 - 1.0uF 20% dipped tantalum capacitor
1 - 1.0 M Ohm 1/2 Watt 5% Carbon Film Resistor

There you have it cagranitz, doesn't get much simpler than this.
Interrupts the O2 sensor signal and attenuates it, outputting a reduced amplitude and phase change.

 

How much would you pay? :twisted:

 

There are some things that can be altered in freessm, but that is dependent on what is supported on your ecu. For example, the center differential clutch pressure can be altered on my car. There are a few other things in the ecu. The available parameters will vary depending on your ecu/tcu, but there are tons of options. It allowed me to monitor both atf temp sensors while towing a 4klbs trailer.

Thanks for posting this ntippet. It's an amazing tool that I've been trying to get people to use for a long time now. I was just too lazy to do a good write up. The only downside is that you need a netbook or laptop for this to work. It also works on linux, which means maybe someday someone will get it working on android!

So you didn't have to set anything up with the vag-com cable? I though the tactrix drivers were required. I had to do it anyway for romraider, so I didn't consider that it wasn't necessary for freessm.

I haven't messed with it in a while, but I don't remember being able to disable codes on it. I know you can with romraider though. BTW, I think changes made with freessm will go away if you disconnect the battery.

 

I could see this being used very very easily on a Car PC.
You are definitely right about using this on a smartphone, I don't think it would take too much work.
Although I can't write that one up.

Nope no drivers required, the cable came with a CD and I never touched it.
Plugged into computer, recognized, done. Selected the COM port.
Tested it on XP and 7.

Good to know about RomRaider, I will have to dig into that some more.
Thanks for that. :29:

 

I could see this being used very very easily on a Car PC.
You are definitely right about using this on a smartphone, I don't think it would take too much work.
Although I can't write that one up.

Nope no drivers required, the cable came with a CD and I never touched it.
Plugged into computer, recognized, done. Selected the COM port.
Tested it on XP and 7.

Good to know about RomRaider, I will have to dig into that some more.
Thanks for that. :29:

Tested it on Win 10 & 11 and works.

 

The problem with romraider is that it is for tuning. It only supports the ecu's with enough demand for opensource tuning. It's mostly the turbo models, but there are a few NA models supported. Also look into ecuflash. It may have different ecu's supported and allows for a bit of rom editing.

 

Nice circuit hack I may have to try that.

I am still wondering if something can be adjusted in the ECU to eliminate the P0420 problem.

Considering that that P0420 problem could be fixed with a $5.00 anti-fouler or $4.00 in electronic components, $15.00 seems fair to be be able to fix it directly in the ECU with FreeSSM

 

Nope sorry, there isn't an option for that in FreeSSM.

 

I have to check out this FreeSSM thing. I just got the Ultragauge and its pretty cool. But I want to change the TCU programming to hold 4th gear longer and prevent upshifts into third until I go past 50% throttle opening...

Hopefully the software and USB drivers runs on Windows 7 64-bit... otherwise I gotta dig up a 32-bit Windows XP laptop...

 

It runs on Windows 7 64bit.
Already tested that.

 

And ubuntu and win 7 32 bit.

I'm not sure it will allow you to alter shift points. I know on mine, I can't really mess with anything in the transmission, just the transfer clutch. I'm really mad that you can up the line pressure for shifts on your transmission. That's the only thing keeping me from more power. I don't have that option!

 

Muahahahaha!!!!
Honestly I am NOT going to touch them.
My transmission works just fine

There is 1 parameter I wish was there though:
Torque converter clutch disengagement correction.
Something based on engine load or throttle %, its tough to get it to disengage and hold 4th gear for hills.
Usually it just jumps all the way down to 3rd.

 

Dude, that is the EXACT thing I want to correct on the 4EAT in my 2003.

In our 2005, with the updated 4EAT with the manumatic mode, it is SOOOOO much better. You can have it hold any gear and it won't EVER upshift. And it will only downshift for you if the RPM gets under 1400 RPM or so it doesn't stall out or overheat the transmission. Its actually one of the better programmed auto-transmissions I have driven. But the 2003 has a lot of room for improvement.

 

Tell me about it. I'm seriously thinking of wiring in a control switch for the tcc. Id prefer to take control of it completely. I think id save a bunch on gas around town. A 3500 rpm stall speed is horrible for city mpg. Just have to remember to disengage before stopping...

 

Yeah I am thinking about doing that too.
Maybe modifying the gear selector & mounting a switch is under the ring or pointer finger.

But then would have to fool the TCU in thinking everything is still normal.
Would probably throw codes. P0741, 77 & others.

 

I can live with a trans code as long as it doesn't put into some sort of limp mode.

 

I was thinking about putting a button on the steering wheel next to the gear selector buttons. Id have to have an auto mode for the wife though.

 

Yep the TCU likes to take it to the highest gear as quick as possible, then stay there...
Which isn't a bad strategy but I would like it to disengage quicker.

I would only want to disengage the TCC and move it to a dummy load, with a simple switch.
This would be much much simpler than taking total control of the solenoid (ON and OFF).
Since the TCU probably controls the solenoid via a duty cycle, ramping up % to avoid driveline shock.
I could build a controller to do this as well but I don't feel its worth it.

Also turning it on by supplying direct DC 12v via a switch is not the best idea IMO.

I might back-probe this circuit and test how it is controlled.

 

If I already have a Tactrix cable, will it work with FreeSSm? Any new/different drivers needed?

(please note, I only know enough about Tactrix and romraider to clear the codes associated with stuck air injection valves - I am no expert/tuner whatsoever!)

 

For those of you with automatics that report, binding or grinding while cornering at low speeds (parking lots, ect...)
I have successfully reduced the symptoms by adjusting the Transfer Duty Ratio Correction.
Note: Increasing this value for 04'+ does decrease the Transfer Duty Ratio %, my electrical monitoring testing verifies this.
03' and prior should be reversed, please perform your own testing to verify this.

My 2001 Outback 4EAT Limited does this exact thing so what should I adjust mine to?

 

Well if anyone is interested here is how the TCU strategy works for the TCC.
Had a few minutes to backprobe the circuit under operation.
Its control is similar to the transfer solenoid.

12V VDC constant 50Hz power side switched
Grounded inside the transmission
PWM controlled
13.4 ohms resistance across the solenoid and circuit

TCC operation stratgey:
Condition | Duty Cycle | Amperage
Off | 5.0% | 0.01A
4th gear On (holding speed or accelerating) | 95% | 0.9A
4th gear On (off throttle de-accelerating) | 40% | 0.3A

The TCU slowly ramps up the % duty during engagement, ~3 seconds to go from 5% to 95%.
Once there it holds 95% duty until you let off the throttle, it then drops and holds at 40%.
Hit the throttle again and once more it ramps up slowly to 95% ~2-3 seconds.

 

cool info!

Um, I once read a rumor that SELECTING low gear will 'lock' the duty cycle close to 50% or w'ever it takes to create '4wd'. Maybe you could check for that? or is the TCC a different thing than the clutch-pack control solenoid?

 

If you want to read about how the transfer solenoid controls power delivered to the rear wheels, go to:
http://www.subaruoutback.org/forums/66-problems-maintenance/11857-im-unhappy-subaru-awd-11.html
Post #110.

The TCC is the torque converter clutch.

 

thanx - my wife's 03 then works the same but with inverted duty cycle numbers. Got it.

 

Seabass you should test your 5eat transfer logic and post up your findings, similar to how I tested mine.
Maybe we should create a chart showing the differences in the power delivery to the rear wheels & circuit control for the different models. 4eat, VDC, 5eat, ect....

 

Does the 4eat do that in overdrive?

The data being provided by ntippet and Seabass is invaluable to understanding the AWD system, and I again express my thanks.

Seabass's question about the duty cycle when in 4th gear (4EAT) and when in 4th with the TCC engaged would be an interesting addition. As the 4EAT (and, incidentally, the CVT) have no means other than the clutch to transfer power to the rear drive train, it seems to me that even when cruising, the duty cycle would be at least that base level of around 42% (http://www.subaruoutback.org/forums...rg/forums/66-problems-maintenance/11857-im-unhappy-subaru-awd-3.html#post365842) This might well be different in the 5EAT which has a mechanical, planetary gear center differential that is always sending power to both the front and rear drives.

Is the FreeSSM able to track/record monitoring data over time or is it only "snapshots"? I'm wondering if it can be set up to record, for example, vehicle speed, gear, throttle position (%?), and AWD duty cycle (%) and perhaps others, so that the relationships can be more easily identified and illustrated.

I also have a center diff so I'm sure the logic that controls the transfer clutch is different. In 1st gear manual mode, the transmission goes into full line pressure holding the gear. It is not full pressure on the transfer clutch. Also in 5th gear, the center diff remains open.

Seabass: So the duty cycle in the 5EAT drops away when in 5th gear? How low? Also, what about the "starting positions" of the other manually selected gears as ntippet reported in the linked thread? Is it the same, around 40% for each?