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5EAT TCU Reverse Engineering


utc_pyro

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Hmm. Didn't someone make a "shift-kit" for the 4EAT, where you can pick any gear you want at will with a joystick-like 4-position shifter?

 

All the shift kits, and stand alone control boxes that I can find are for the earlier 4EAT's without direct control valve bodies, mine has a direct control valve body, like the one in the 5AT

 

How new (or old) is the update? As in release date or something?

 

Not sure how long the 05 flash has been out, but the 08-09 one has been out for at least a year if not longer, and there is only one update for each

 

They don't mention it unless you have issues related to what it fixes.

 

Correct, if your car had a DTC that the reflash fixed in the TCU, they would flash the TCU

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i think if you have an 05.5 it has already been flashed. i think that update is the difference between the 05 automatics and the 05.5 automatics. though i could be wrong, since the ECU is read as different between the 05 and 05.5
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Resistor pix.

 

Could not get my meter on it as the ends are insulated. I can pull some back, it will be difficult to get my leads up where the resistor is.

 

Also, I traced the wires into the harness. Without removing more to get to where they taped up their splice I can not see the connections. I took a pic to show how far up the harness they ran the wires.

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650860009_vb002.thumb.jpg.ef9f4a13b3c9a2324f3904fcd9693acf.jpg

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I may try this, I bought a tool to extract the wire from the connection harness (again I do not want to cut the wire) hopefully the tool works.

1. Buy the resistor, theres a guy on ebay selling a 5pack for $10 - I know its a hit/miss on ebay

2. Hopefully a pc power supply pin plugs into the tcm wire harness

3. I need to know the pin# and/or the color of the wire to splice

When and if I do this Ill report back with the results, if i feel a difference

 

the link from the guy im most likey buying from ebay

Edited by underground000

5eat downshift rev match:):wub:

Powder coated wheels: completed:)

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m sprank, where is the harness located at in relation to the transmission? ex: front passenger side of the car.... Its hard to tell by the pictures.

 

I would also be interested in trying out this modification. My only concern is if the resistor is the same size between the different years of transmissions. I doubt they are since IPT had to test a lot of m spranks car before they felt the end result was correct.

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Climber wins is second chicken dinner of the last month.

 

Sorry was basically upside down and backwards taking that shot. With one hand I had the camera and with the other I was holding the wires (out of the shot) to help show how far up they went into the harness.

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You know what we kinda forgot about? The ability to read the ATF temperature. I simply don't know what that is reported by or where the sensor is located and HOW it is reported (does it go to the TCU/ECU, or straight to the light on the dash?) but we know there is one.
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You know what we kinda forgot about? The ability to read the ATF temperature. I simply don't know what that is reported by or where the sensor is located and HOW it is reported (does it go to the TCU/ECU, or straight to the light on the dash?) but we know there is one.

 

I've done some more research, and it's probably reported to the ECU. We just need to find a way to add a few ranges to RomRaider and then figur out the scaling/offset. Maybe NSFW could help as he seems to be quite active on there forums finding new definitions?

 

Probing my car via SSM never got a response from anything but the ECU, so it must be the "gateway" to the CAN bus. That or this SSM "port scan" application that was given to me still does not like my laptop.

 

We actually have TWO temp sensors in the 5AT, one right after the torque converter (hottest place) and one in the pan (or the return from the cooler). These are NTC thermistors, and report directly to the TCU (it has a few analog inputs).

Edited by utc_pyro
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If there is an ATF temperature sensor signal in the ECU, finding it would be hard.

 

If it's communicated to the ECU via the CAN bus, that's going to mean reverse-engineering complex code that I have no other interest in, which makes it a low priority for me. If the ECU has a dedicated input for it, then you could follow the wires to the circuit board, and follow the traces to pins on the CPU. I could then find the code that reads the signals at those pins. That's harder for you, but easier for me. :)

 

Has anyone confirmed the existence of a temp sensor on the transmission? If so, do the wires lead to the ECU, or to the TCU?

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If there is an ATF temperature sensor signal in the ECU, finding it would be hard.

 

If it's communicated to the ECU via the CAN bus, that's going to mean reverse-engineering complex code that I have no other interest in, which makes it a low priority for me. If the ECU has a dedicated input for it, then you could follow the wires to the circuit board, and follow the traces to pins on the CPU. I could then find the code that reads the signals at those pins. That's harder for you, but easier for me. :)

 

Has anyone confirmed the existence of a temp sensor on the transmission? If so, do the wires lead to the ECU, or to the TCU?

 

FSM for 5eat unit says 2 temp sensors. They supposedly go to TCU. I'm 99.9% sure nothing like that goes to ECU as I am freshly familiar with ECU pinouts. However, they would most likely be analog and therefore very easy to read as a lambda with a gauge if anyone was so inclined. But the scaling...

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connector B54 of TCM pin #2 = ATF sensor 1, measures temp of fluid in pan. should get approx 2.5V when fluid is approx 68deg F, approx 1V when fluid is 176deg F

 

Same connector of TCM pin #11 ATF sensor 2, measures fluid temp of torque converter outlet. 2.3V cold, .6V hot

 

Both sensors are attached to valve body

 

I have the TCM pinouts if anyone is interested, I'll try getting the wire colors later as both connectors to TCM are the same(05 Legacy anyways), will require more digging in service manual

 

Google: "techinfo subaru" and subaru's tech information site should come up. For a fee, depending on how long you want access, you can see service manuals and download pages. I can't remember if there's a download limit or not

 

Or let me know what you guys need, and I'll try to get it for you

 

I haven't been able to get the wife's car and the ssm3 in the same spot to check her TCM cal id. Would the program you are trying to use to scan for the TCM help if it can use the reflash?

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If they're 0-5v, and you've removed your TGVs, you could probably hook them right up.

 

I'm always on the lookout for fun stuff to do with those. :)

 

Even if you don't know the scaling, you could at least get a sense of what's normal and what's outside the normal range.

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NSFW, it's not going to be that bad ;). The info is already published, it's part of the documented paramiters in SSM that Subaru published (or leaked?) for third partys to make scan tools. It's aprt of the basic peramiters that the Rom Raider team never figured out, they just didnt have cars that were reporting this info.

 

There is a post over on the RomRaider forums where Merchgod(?) filled in the list of missing data values compared to a legacy GT ecu init string. Looked like they matched up right in order with the Subaru document, but there was no intrest in writing the definitions to match for the Logger.

 

I'd do it my self if you could give me a few pointers were to start. Just the logger definitions, nothing in the actual ECU.

 

I have the TCM pinouts if anyone is interested, I'll try getting the wire colors later as both connectors to TCM are the same(05 Legacy anyways), will require more digging in service manual

Can you get sme more detail on the wires that goe to the valve body that are just a block saying it goes to it? I just got a logic analizer (it literally just got here yesterday) so I can sniff them my self now, but it's not going to be easy figuring it all out that way. Spesifically, we need to know what pins are what solonoids.

 

Or let me know what you guys need, and I'll try to get it for you

I haven't been able to get the wife's car and the ssm3 in the same spot to check her TCM cal id. Would the program you are trying to use to scan for the TCM help if it can use the reflash?

Eh, I doubt it seeing as I never saw anything else respond except the ECU. What we'd need to do to get better info on how to interface with the TCU without cracking it, we'd need to sniff your SSM3 tool while it's talking to a TCU. That said, what state are you in :)

 

Really I need to figure out what standard those 9 debug pins on the TCU board are and what the CPU is based on to get started with reverse engineering it. Without that, we can only find work arounds (resistor mod, logging support, maybe a piggyback).

Edited by utc_pyro
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Ok, well the wiring diagram for the 5AT just shows all the wires going to a box(the valve body), but if you use both the TCM pinout and wiring diagram, you should be able to figure out which wire goes for what.

 

I'm about 30min- 1hr North of Chicago, IL, depending on traffic and how fast you drive:lol:

 

I've sent you a PM

 

B54 is white in color, ATF temp sensor 1 should be a white with green stripe wire at the TCM, sensor 2 is a light green with white stripe

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