5.0 Explorer trans problem after swap. | Ford Explorer Forums - Serious Explorations

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5.0 Explorer trans problem after swap.


March 30, 2015
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Year, Model & Trim Level
1993 BMW E36 325 302 swap
Hello, so my problem is, when I start the car in park it starts fine no problem. But when I put it in gear (any gear) the motor just dies. If I put it in gear and let go of the brake quickly it takes off no problem and drives. I am getting codes on all 3 solenoids(Dont remember the code names). The motor is a 1999/2000 and the trans is a 1996. PCM is also 1996.
Now the question is, is the wiring loom diffirent for the 1999 4R70W and the 1996 4R70W? Could there be a ground or positive wire missing to the trans?
I find it very unlikely that all 3 solenoids have failed.

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You need to repin the valve body plug. The 96 harness has 3 power inputs where 98+ only has one. I cut off a 98 plug and attached it to my 97 harness in my swap.


Thanks for the quick reply! Do you happen to have the wiring info?

Well my problem is not fixed. Turns out my transmission wiring loom was the earlier style, so I cut the loom and reconnected wires of the same colour.
Does anyone know if the 1996 and 1999 PCM have different ports for the trans? That is the output of the PCM. Dont have the vehicle in front of me.
I am thinking I might need to repin the main connector to the PCM?

repin, or cut and splice the connector at the trans like Centaurus5.0 said. i have a 96 trans in my 98 and thats what i did and i have no problems with it

Technically he was right if i understand his issue. What I said would work if he was running a 96/97 harness with a 98+ trans. I think he has a 99? Trans wiring.

98+ trans harness only have power supplied at the trans connector for the solonoids in 1 spot. On the 96-97 it's in 3 places.

To the OP: What year engine harness and transmission harness are you using? What 4 letter PCM code are you using?

I am using a 99 engine, 99 engine loom, 96 trans and 96 trans loom. PCM is a 96 SLL4.
The big connector from the PCM to the TCM that has about 30 wires in it, essentially where I can remove the wiring to the trans. I took that connector apart and checked wire numbers/colours by the ports, they did not match. So I went ahead and tried to repin the plug, and to my luck that was not possible, because some of tue wires were bigger and did not fit thr corresponding wire in the plug.

So I cut the harness and connected everything back together, and all wires matches no problem.
But the problem is still there, that is why I am wondering if these diffirent PCM's have a diffirent port in the pinout to control the transmission.

I would try to find a 96 or 97 engine harness to swap in. You will also need to swap over to return style fuel system to run that 96 computer along with a 3 wire cam pos sensor. The egr is also slightly different but that's not a big deal right now.

Well explorers here in Iceland are very limited, only 2 are remaining with the 5.0.
The motor is up and running, I have a tuner that is mapping the computer, car will be datalogged with an air/fuel meter to ensure the motor is getting the right mixture. Otherwise I will buy the return rail. Importing stuff to Iceland is rather expensive, shipping is expensive and then tax will go on top of the total including shipping.
I am leaning towards a full manual valve body to put into my trans, that will eliminate all the wiring issues. And since this car is going to be a track car, the full manual valve body will be great, then later with a higher stall converter. I have given up on letting the PCM control the trans, this has been way too much of a headache. The trans will be programmed out of the PCM.
I would like to however thank you for all the given help. Always nice to get quick and good information.
Thanks again guys.