Tach signal?

[Sleeper]

Not sure where to post this...
Does anybody know if the the tachometer signal coming from the CCCI is converted from pulse frequency to voltage? Is there any RPM signal within the ECM that is converted to voltage?

Thanks,
Paul

[Eric Marshall]

I don't think so Paul. I believe its all frequency based. There is a pulse accumulator in the ecm that is used to calculate the RPM.

I take it you need an analog RPM signal for something?

[aminga]

I don't think so Paul. I believe its all frequency based. There is a pulse accumulator in the ecm that is used to calculate the RPM.

I take it you need an analog RPM signal for something?
There is a distributor reference output near the AC compressor, green wire with black plug.

[turbodave]

Ummm, actually, the tach reference signal is the "green" connector. It has white wires.

[Sleeper]

I don't think so Paul. I believe its all frequency based. There is a pulse accumulator in the ecm that is used to calculate the RPM.

I take it you need an analog RPM signal for something?


Hey Eric,
Thanks for the confirmation. (I spoke to Bruce as well) You are correct, I was hoping to find a way around having to buy an frequency to voltage converter, so I can data log RPM with a WB O2 setup.

Thanks aminga, but that plug in location is a pulse signal.

Paul

[aminga]

Ummm, actually, the tach reference signal is the "green" connector. It has white wires.
That's what I get for relying on memory instead of going out there and looking.