Re: OBDII Mt conversion???
 

Damn, that is not what I wanted to hear guys! I was hoping all these years later that a fix would have been discovered.

Still up for that challenge? I think my flex plate took a dump, so I'm begrudgingly collecting parts for a manual swap.

Tom, do you still sell modded pedal boxes and shift linkages?

Re: OBDII Mt conversion???
 

You realize that post was from 6 years ago. It is common knowledge now. Both him and I are telling you and anyone else that wants to keep asking, that it will have a permanent CEL from the lost comm link.

Re: OBDII Mt conversion???
 

Doesn't do much good when the thread's topic doesn't have a resolution, now it does! :)

Would it be possible to take a freeze-frame or a few seconds worth of data from the TCU and send a loop of that data to the ECU to trick it into thinking that the car still has an automatic?

Would simply leaving the TCU plugged in and in place on the car be enough to get around this CEL business?

On a slightly related side note, has anyone ever converted an OBD2 car back to OBD1 ECU/wiring/TCU to get around these issues?

Re: OBDII Mt conversion???
 

There will be sensors and such that are missed by the TCU due to the lack of an auto transmission that will result in other errors.

Changing it to OBD1 wiring ought to work fine for getting rid of the CEL, but it wont' pass emissions testing or whatever due to the lack of OBD2. Actually, the thing to do would be to build an OBD2 - OBD1 adapter, then just plug in the OBD1 ECU. I think Young Tom made one, and I'd be up for the challenge if I had an OBD2 pinout.

Re: OBDII Mt conversion???
 

Ok, so it is a digital signal. Have you seen it to know what is being communicated? First off, it is one line so it is likely one way data from the tcu to the ecu. Second, obd2 is not required to report tranny data so it is unlikely that there is a ton of information being passed. It is probably a simple "ok" signal or a signal reporting the obd2 error code.

Re: OBDII Mt conversion???
 

This is what I was hoping it was. It's not CANBUS or anything, we're talking 1996 here... Can't be that complicated, right? :D

A jumper to an OBD1 ECU would be great, then I could take advantage of all the upgrades.
1) Has this been successfully done before? How close were any stillborn projects to completion and what caused the demise?
2) What would be involved? Could a few signals be tricked and work like OEM, or...?
3) Is this a worthwhile endeavor, vs. an aftermarket EMS?

Re: OBDII Mt conversion???
 

Yes i made a jumper for obdii to obdi. Yes it works. Its worthwhile because you will need it to go along with a standalone ems anyway.

Tom

Re: OBDII Mt conversion???
 

Where did you get the pinout for the OBD2 ECU? I haven't come across one yet as far as I can tell.

Also, did you use twisted/shielded wires for the crank/cam wires?

Re: OBDII Mt conversion???
 

I had it on my old mitchel on demand cd.... old school members will remember i did a fundraiser for the network with them... dont have them anymore tho

I did not use sheilding as it was prototype work... but twisting the wires will work fine. In all reality the wires are not long enough to require it

Tom

Re: OBDII Mt conversion???
 

Ok, cool. I'll see what I can find.

Re: OBDII Mt conversion???
 

If you look back you will see that I broke down the wiring and pinout differences. They are minimal except for that damn diagnostic signal going to the OBD2 ECU. Wanna work on this together? When things calm down after Christmas I was hoping to tap into that diagnostic signal and record it.

Re: OBDII Mt conversion???
 

Sure. Where did you post that?

Also, I have a 94 and 97, and you have a 96. That should represent all of the TCUs and ECUs. Can you take a pic of the TCU and ECU, where the plugs go, so we can verify the exact wiring of each of them?

I am thinking I can take the plugs from my spare body harness (or find new connectors) and a DIY BOB from here and make an adapter if someone needs one.

Re: OBDII Mt conversion???
 

I still have my old jumper if any of you are interested

Tom

Re: OBDII Mt conversion???
 

Sure. How much do you want for it?

Re: OBDII Mt conversion???
 

Is it a jumper for OBD2 ECU to OBD1 ECU or OBD2 TCU to OBD1 TCU?