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Author Topic: Constant Powere to ECU Required?
Teamfour Verified Driver Made Donation to Website
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Region: WDCR
Car #: 04
Year : 1993
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Back when I raced my Factory Five Cobra, I rigged the master switch with a fused jumper that would provide a constant 12v to the ECU even when the switch was off.

Is this necessary or beneficial for an SM?

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Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

davew Verified Driver Made Donation to Website
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It would not be legal

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Teamfour Verified Driver Made Donation to Website
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Well I was looking for the technical answer, but it looks like we will go down the legality road instead. (where is the can-o-worms icon?)

In a stock configuration, the ECU has constant power. If anything, interrupting the power to the ECU via master switch would seem to be construed as modifying the circuit and therefore illegal.

--------------------
Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

davew Verified Driver Made Donation to Website
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The power is turned off by the master switch by design. Installing "a fused jumper that would provide a constant 12v to the ECU even when the switch was off" would be the illegal modification.

My initial reaction would be that you are doing something to the ECU that requires constant power. But your reason could also be inocent.

Dave

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Teamfour Verified Driver Made Donation to Website
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quote:
Originally posted by davew:


My initial reaction would be that you are doing something to the ECU that requires constant power. But your reason could also be innocent.

Dave

It is very innocent. My EFI 5.0 did not like being reset due to power disruptions. It would have to "re-learn" some mapping/trims in order to idle well. I just wondered if the SM ECU was similar.

--------------------
Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

Cajun Miata Man Verified Driver
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Lee,

It won't do any harm to take power off the ECU. I have always taken the power off by turning off the master kill in all of my 4 SMs over the years. Never an issue.

--------------------
James York


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You could also just leave the master switch on and turn the key off...just like stock.
If it's that large of a concern.

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If you can't fix it with a hammer, it's got electrical problems.

JIM DANIELS
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These ECUs will not lose anything by powering down so K.I.S.S.

Teamfour Verified Driver Made Donation to Website
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quote:
Originally posted by JIM DANIELS:
These ECUs will not lose anything by powering down so K.I.S.S.

Hey, who you calling stoopud? You must mean "smartone". [Smile]

Thanks everyone, even you Jim. [Wink]

--------------------
Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

   

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