anyone have a 2004 RL shop manual???

[my_bd]

if so,
could you lookup a tach lead source?

thanx!

[pclear9061]

did you look at the pcm thread that i posted???

[my_bd]

Originally Posted by pclear9061

did you look at the pcm thread that i posted???

yes, but i don't see a reference to the tach,

[Sp00ner]

http://www.redlineforums.com/forums/...achmentid=1277

Does that help or no?

[my_bd]

Originally Posted by Sp00ner

http://www.redlineforums.com/forums/...achmentid=1277

Does that help or no?

i don't see a specific reference to tach/rpm signal, but there is that pin31 engine speed signal uxe, i wonder if that is it?

[Sp00ner]

Originally Posted by my_bd

i don't see a specific reference to tach/rpm signal, but there is that pin31 engine speed signal uxe, i wonder if that is it?

I'm pretty sure. That's the one I have to tap for the ladder tach. Seems like the right one. I think there's a better one than tapping the computer lead though. Try PMing JPK, WopOnTour, Ummm... BlackLine... I think these people have all installed a shift light before. Same deal I would assume.

[Sp00ner]

Even better!

http://saturnspeed.com/yabbse/index....threadid=21343

Try this one!

[mailmars]

Originally Posted by Sp00ner

I'm pretty sure. That's the one I have to tap for the ladder tach. Seems like the right one. I think there's a better one than tapping the computer lead though. Try PMing JPK, WopOnTour, Ummm... BlackLine... I think these people have all installed a shift light before. Same deal I would assume.

PCM C1-31 is used for the OEM ladder tach. It is not a raw analog signal so if you are using a aftermarket tach then the location would be per the link by Sp00ner in message #7 of this thread.


Mark

[WopOnTour]

Long story short... there is no raw TACH lead on the LSJ
(Pin 31 on the ECM is a pulse-width digital signal meant for the ladder tach only)
Those boys on SaturnSpeed appear to have tapped into the Ignition Control (IC) circuit for cylinder #4 - which MAY work for certain tachs and shiftlights that have a 1 cylinder setting. This would be neccessary as it is only pulsed once every 2 engine revolutions to trigger the #4 Coil On Plug module and produce a spark.
While this MAY work without issue, I for one would be concerned about the effects of the parallel resistance or capacitance of the tach/shift light on the spark control waveform as it COULD affect the event somehow on cylinder 4 IMO. Doesnt hurt to try though.
I for one would be interested in seeing a side by side scope pattern comparison with and without the tach connected.
JMO
WopOnTour

[my_bd]

Originally Posted by Sp00ner

Even better!

http://saturnspeed.com/yabbse/index....threadid=21343

Try this one!

yes, this is the tap point I am currently using for the Raptor shift light,
and interestingly, the shift light has to be set to the "1 cyl" mode in order to work with this wire tap point.

I am curious about the reason for that.

I found this tap point to be very awkward to get at, and a bit suspicious since I have not found any 'official' documentation vis-a-vis the shop manual query.