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minytrker
May 22nd, 2009, 07:44 AM
How can I run an autometer tach with a E38? What do I need to change the tach signal to in the pcm?
minytrker
May 22nd, 2009, 09:11 AM
need help asap!! have to have this finished by tonight
GMPX
May 23rd, 2009, 09:00 AM
The ECM Output needs a resistive pull up to 12V. Put one side of a 1K resistor on the Tach output pin the other side to 12V IGN. Unfortunately the ECM has no built in 12V pull-up like the old LS1 PCM did.
Might want to also check if the Autometer has the pull-up built in. I don't think they do though as this small mod has needed to be done on every Autometer Tach I've seen on the E38 / E67 installation.

Cheers,
Ross
minytrker
May 24th, 2009, 02:50 AM
So the 12v side and the tach wire will be on the same connector?

What do I need to set the tach at in EFI?
GMPX
May 24th, 2009, 07:55 AM
So the 12v side and the tach wire will be on the same connector? No, you don't connect the tach wire to 12V.
On the tach pin (on the ECM), connect the tacho wire, then on the same pin put one end of 1K resistor, the other end of the resistor goes to the 12V IGN.


What do I need to set the tach at in EFI?I have a feeling the tach signal is always there. I don't have EFILive on this computer to confirm the setting but if you just change it from Serial to Crank (or something like that) it should be fine.

Cheers,
Ross
minytrker
May 24th, 2009, 08:44 AM
Im still lost, like this? Sorry the horrbile drawing just did it really quick in paint.
GMPX
May 24th, 2009, 10:57 AM
Spot on Lorenz, that is how it needs to be.
I just looked at the file I had done for the E67 conversion I assisted with and the Tacho is set to Crank. Then change the pulse count on the High and Low to match the RPM in the scantool to that shown on the Autometer Tach.
gmh308
June 7th, 2009, 10:25 PM
Spot on Lorenz, that is how it needs to be.
I just looked at the file I had done for the E67 conversion I assisted with and the Tacho is set to Crank. Then change the pulse count on the High and Low to match the RPM in the scantool to that shown on the Autometer Tach.

Was this one of those E67's from the GMPP kit Ross? :)
GMPX
June 8th, 2009, 02:05 PM
Yes, but it was reflashed to a standard GM calibration as the GMPP refused to run the engine (not sure why). I think we just stuck a 2006 CTS-V tune in it.

Cheers,
Ross
gmh308
June 8th, 2009, 02:34 PM
Yes, but it was reflashed to a standard GM calibration

as the GMPP refused to run the engine (not sure why).

I think we just stuck a 2006 CTS-V tune in it.

Cheers,
Ross

Well I guess that's a good start :). One of the "hidden" extras required. :shock:
ScarabEpic22
June 8th, 2009, 04:16 PM
Ive heard its common for the GMPP E67s to be picky about running or not and a lot of guys just throw a stock tune in them to solve the problem.
gmh308
June 8th, 2009, 06:27 PM
Ive heard its common for the GMPP E67s to be picky about running or not and a lot of guys just throw a stock tune in them to solve the problem.

But you would think a GMPP item would be right? Though maybe they didnt know they needed to be "woken up" from the factory fresh state? :shock:

Many dealers dont....:hihi:

Cheers :cheers:
ScarabEpic22
June 11th, 2009, 04:50 PM
But you would think a GMPP item would be right? Though maybe they didnt know they needed to be "woken up" from the factory fresh state? :shock:

Many dealers dont....:hihi:

Cheers :cheers:

I cant say, Ive just heard people are having issues with the GMPP cal that comes with it (dont know what it is) so they flash a regular production tune in and it works. Who knows, if someone figures this out please let me know just for the sake of knowing!