# ECU -using a 5 speed ECU in an auto. car
**URL:** https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631
**Category:** SON240sx Automotive
**Created:** [August 11, 2008, 4:21pm UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631 "2008-08-11T16:21:21Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@john\_gto](https://forums.speedlife.net/u/john_gto)
#### Post date: [August 11, 2008, 4:21pm UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/1 "2008-08-11T16:21:21Z")
Here is the question- can you use a 5 speed sohc ECU in an automatic sohc car.
I know that the use of an auto ECU cuts the speed limiter in a 5 speed car but does anyone know what the issues are when you use a 5 speed ECU in an automatic. (I have been looking for a replacement sohc auto ECU for some time ) Any factual input is appreciated.
Thanks. John
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### Author:  [@Jowo72](https://forums.speedlife.net/u/Jowo72)
#### Post date: [August 11, 2008, 4:28pm UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/2 "2008-08-11T16:28:03Z")
I’m pretty sure the auto computer has shift points programmed into it, if i had to wager i’d say it may work, but your engine light will probably come on and your tranny will shift like garbage, if atall.
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### Author:  [@Osad](https://forums.speedlife.net/u/Osad)
#### Post date: [August 12, 2008, 1:59am UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/3 "2008-08-12T01:59:36Z")
It won’t even let you start the car. You would have to re-wire all the inhibitor switches and tranny sensors. It’s a mess.
Why would you even want to do this?
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### Author:  [@john\_gto](https://forums.speedlife.net/u/john_gto)
#### Post date: [August 12, 2008, 1:26pm UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/4 "2008-08-12T13:26:30Z")
Thanks for your input so far. I am trying this since the only SOHC auto ECU’s I have found have the same moisture damage as the original (usually causing 1 or more injectors to stop working) . As of yesterday I am using a stock SOHC 5 speed ECU and so far (30kms or so) all seems to work normally.
Has anyone else tried this ? BTW original auto ECU # 72 ,next auto ECU #13 and current ECU (removed from a 5 speed)#10
Thanks John
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### Author:  [@Osad](https://forums.speedlife.net/u/Osad)
#### Post date: [August 13, 2008, 3:09am UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/5 "2008-08-13T03:09:36Z")
Now that I think about it, If you keep the auto tranny computer plugged in, it may still work decently. The ECU controls mainly the functions of the motor, the tranny computer will control shift points and such, of course these 2 do interact, so Im thinking there must be some point at which there will be a miscommunication between the 2. But for day to day, it should be fine…
Let us know how it goes.
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### Author:  [@john\_gto](https://forums.speedlife.net/u/john_gto)
#### Post date: [September 14, 2008, 5:21am UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/6 "2008-09-14T05:21:59Z")
Update
Have been using this setup for a month on a daily driver -no problems or gremlins so far.
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### Author:  [@Osad](https://forums.speedlife.net/u/Osad)
#### Post date: [September 14, 2008, 4:30pm UTC](https://forums.speedlife.net/t/ecu-using-a-5-speed-ecu-in-an-auto-car/117631/7 "2008-09-14T16:30:42Z")
Cool man. That’s an interesting situation haha!