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View Full Version : difference in auto and manual ECU'S?


240silvia
09-28-2005, 03:02 PM
well i know the obvious, one is for manual and one is for auto. but i also know u can run a 5spd 240sx with a auto ecu. but can u run an automatic 240sx with a manual ecu? if not, why? and is there something that can be done to be able too.. thanx

DP_Michelle G
09-28-2005, 04:22 PM
I talked to my bf and he said. The auto ecu will work (given that it's the correct one for your motor), however you will run into problems with your speed governor and/or rev limiter and check engine light (A/T signal). And you'll hit fuel cut-off much sooner than you should. Oh he also said the car will run like shit

240silvia
09-28-2005, 05:24 PM
I appreciate your response, but, I have had 2 automatic ECU's in a turbo 5 speed and there weren't any problems. My daily driver car (automatic), and my friends car (5-Speed), we are trying to figure out if there are any differences in the fuel curve. I know that the auto doesn't have a speed limiter, which is why my friend wants my ECU. However, we are wanting to know if the manual ECU will work in my auto without any problems.

-Charles

omgosh
09-28-2005, 08:01 PM
Well if the auto trans controller is part of the ecu, then no..

Just switch em, it'll take like 5 minutes.

projectRDM
09-28-2005, 09:20 PM
5spd ECU will not run an automatic equipped car, the communication line between modules does not exist in the 5spd harness.

It works the other way because the auto ECU doesn't see the signals from the transmission computer in a 5spd car, but it doesn't need them to run the motor, whereas the transmission module in an auto car needs those inputs in order to shift/drive properly.

You might can use it to diagnose a MAF/CAS/CTS/TPS problem, but that's it.

And Michelle, you're 'bf' is wrong on all points. An auto ECU in a 5spd car will not see any fuel cut or any speed/rev limiter limitations at all. Opposite of the 5spd ECU's control.