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ECU wiring - Control Unit Power Supply

GTaaargh

By GTaaargh,
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GTaaargh

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Hi.

I looked at the ECU of my 1989 r32 GTR over the weekend and noticed that a bullet connector was not connected. It breaks the connection out of terminal number 49, a 'control unit power supply'. I notice that a gauge draws its power from terminal number 59 which has the same description on the diagram. Maybe they tried to connect the gauge to pin 49 and cut the wire by mistake, fixing it by putting in a pair of bullet connectors.. Who knows.....

Anyway, does anyone know what is driven by terminal number 49? It doesn't seem to have affected the drivability.

Another question: Is it normal to power gauges etc from wiring going into the ECU? Surely it could affect the signal quality, or the amount of power available. Why aren't spare wires in the dash used, such as sharing the cigarette lighter connection?

Thanks.

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GTaaargh Collaborator

GTaaargh

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Anyway, does anyone know what is driven by terminal number 49?  It doesn't seem to have affected the drivability.

To answer my own question: terminals 49 and 59 both seem to have an output of 12V from the ECU. Why? Because the disconnected wire coming out of 49 has 12V on it. I guess both would be the same because the description is the same. They are joined later on in the wiring loom, so they seem to share their power to devices. My guess is that the ECU provided regulated power, and there are 2 leads in case the draw on one is too high.

They appear to power the injector pulse width correction, the air flow meters etc. Not good things to have disconnected

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