Topic: Shift lights - options and installation questions

[Critterman]

There is about 1k between all gears except 4thnd 5th, that is about 500 rpm

[snaponbob]

There is about 1k between all gears except 4thnd 5th, that is about 500 rpm

Huh?

[Critterman]

Are you seeing something different Bob?

[snaponbob]

Are you seeing something different Bob?

"There is about 1k between all gears except 4thnd 5th, that is about 500 rpm"

At what rpm's and road speeds?

[Uranium-238]

So, they're not linear? I thought they were, if time shifting isn't considered. For my test, I shifted as fast as I could, and noted what the RPM jumped down to when I let out the clutch.

[kennysabarese]

I just read this thread at the BB and I don't understand a lick of the info there. This is for a 2.4, but I assume it would be the same for our LNF.

http://www.solsticeforum.com/forum/f48/rpm-pickup-point-46532/

This particular post says you can pick it up off a wire on the ECU

http://www.solsticeforum.com/forum/f48/rpm-pickup-point-46532/#post701825

[kennysabarese]

Ok found this too. Here is one is made by the same people who make a unit that Bob was mentioning in another thread.

http://www.striracing-usa.com/pro_s.htm

It works using the cig lighter according to this old thread.

http://www.skyroadster.com/forums/f44/cs-stri-shift-light-indicator-10874/


"It picks up the RPM signal from the 12v current going to the cig lighter adaptor. I have personally tested it and it works great. First you plug the unit in, put the car in nuetral, rev to whatever rpm you want the shift light to go on, adjust the knob so that the light turns on and youre set to go"

Wonder if that works with the one I just bought.

[snaponbob]

Hopefully this will help. The info on the BB really was more about doing data acquisition, not hooking up a tach light.


Wiring =
Only 3 wires to connect! Ground, Ignition and Tacho.

The tacho input is quite flexible and can be connected to either...

    * 5 or 12V digital tacho signals (ECU to instrument)
    * Electronic ignition outputs (ECU to coil, including wasted spark systems and coil on plug systems)
    * Fuel injector outputs (ECU to fuel injector)
    * Low voltage side to coils as indicated below...

[attachment=1]

Our options seem to be either the first or fourth image. I would think that capturing the tach signal BEFORE it gets to the ecu would be more "real time" and not require tapping into ECU or BCM. Image one shows taking the data from the ECU. The best way is to tap in to the wire coming off the appropriate module, and going directly to the computers make my hair itch. The other way is image 4 which is the low voltage signal from the ECU to the coil, and that can be done at the coil signal lead on any one of the four coils. Tapping into our F.I. lead may not work as I think our injectors multi fire, but not sure on that one.



  

[kennysabarese]

I just wanna know which wire it is!

J1 - 45 & J1-46 on the ECU J1 is from the other thread. Can anyone confirm?

[snaponbob]

I just wanna know which wire it is!

J1 - 45 & J1-46 on the ECU J1 is from the other thread. Can anyone confirm?

J1-45 is a gray wire and is labeled "5V REF 3".
J1-46 is a tan wire and is labeled "LOW REF".
I believe these are feeds TO the crank position sensor which is located on the left rear corner of the block above the the starter.
J1- 35 is a yellow wire and is labeled "CKP SENS SIG".
This one should be the actual position sensor signal TO the ECU.
The crank position sensor has three wires at the plug of the sensor.

Looking at the entire thread, the guy who posted the pin out also corrected himself towards the end for a 2.4 set up. The important thing is that he said he was "assuming". Additionally, he read the wiring diagram incorrectly for the 2.4. Honestly, I am not trying to be a smart ass or appear to be a know-it-all, but the poster on the BB may be a bit off on his info. I am looking at factory wiring diagrams on line at Mitchell. He was correct on the LNF voltage signals TO the sensor, but had not provided the signal path BACK to the ECU. Ecliptech does not show an option for picking up the crank sensor to fire the shift light. Just trying to help.

[kennysabarese]

I'm nervous to be the first one to try since I know the least about this stuff. Don't like cutting wires

I googled around and some people tap it off the wires that feed the tach gauge on the dash. Maybe this is an option for us?

[snaponbob]

I'm nervous to be the first one to try since I know the least about this stuff. Don't like cutting wires

I googled around and some people tap it off the wires that feed the tach gauge on the dash. Maybe this is an option for us?

Our data system is what is called a CAN BUS. This is an information transfer system that multiplexes data as opposed to one signal on one wire. This is from a tutorial page - "The CAN bus (Controller Area Networking) was defined in the late 1980 by Bosch, initially for use in automotive applications." I am not sure if tapping into a tach signal will work. On the Mitchell site it shows a multiplexed signal from the ECU to the gauge cluster. The signal going to a single coil pack is starting to bother me as well as we may have a multi fire ignition system that fires the plug more than once during the combustion phase.

Tell you what. How about if I contact the vendor in Australia and ask them?  If you can wait, I'll try to gather up some more info. It will help BOTH of us, because this is something I want to do on my car as well.

[2kwk4u]

I just did a quick search on www.the12volt.com

It looks like in the alarm/remote install world they tap the signal side of an injector for tach signal:

http://www.the12volt.com/installbay/forum_posts.asp~TID~98450

It says use the wire *opposite* the pink with a black trace.  Without looking I'd say each injector has two wires, one pink/black, and one that is another color or color combo, depending on which injector it is.

[kennysabarese]

Tell you what. How about if I contact the vendor in Australia and ask them?  If you can wait, I'll try to gather up some more info. It will help BOTH of us, because this is something I want to do on my car as well.

I am in no rush. I just know less about car electronics than I do about turning wrenches.

Let me know what you find out

while typing this I was just thinking about the Cobalt and how they use them for drag racing. I found a guy on that forum called msfitoy. His sig says he has one. But I can't find anything. I just PM'd him so let's see if he writes back.

[kennysabarese]

Ok got an answer from him already

http://www.cobaltss.net/forums/showpost.php?p=4487008&postcount=3

"it turns out that none of the wires running to the cluster was suitable for tach signal...you need to tap off any one of the coil...I can't recall which color, but there's three wires going to each...use the one that is common color at all four plugs...hope that helps..."

[kennysabarese]

I just looked. Each cylinder has black brown and pink. then the two other sensors going into the valve cover have pink as well as the the intake tube also has pink.

[Uranium-238]

Well I'm just going to sit back and let you all figure this all out. Payday is Friday, so hopefully I'll have some answers by then.

[snaponbob]

Ok got an answer from him already

http://www.cobaltss.net/forums/showpost.php?p=4487008&postcount=3

"it turns out that none of the wires running to the cluster was suitable for tach signal...you need to tap off any one of the coil...I can't recall which color, but there's three wires going to each...use the one that is common color at all four plugs...hope that helps..."

Not sure what he is referring to.
There are two color wires common to all four wires; one is black (ground) and the other is pink/black which goes to Fuse 45 (15 amp).
Next, there are brown wires common to #1 & 3, and brown/white common to #2 & 4. The brown goes to pin 78 on the ecu which is "LOW REF", and the brn/wht goes to pin 13 which is another "LOW REF".
The remaining unique colored wires to each coil are the IC (ignition coil) signal from the ecu. One of THESE should be the tach signal that is needed.

[Critterman]

Bob,
My car if fairly consistent between gears 1k between first and second, 1.5k between second and third, and 1k between third and fourth, 500 rpm between forth and fifth.  but I have the Colorado truck tranny.   So if I am doing 70 in 5th about 2800 rpm, and want to pick up a smoth 3rd, I need to rev match to 4300 rpm to pick up a smooth 3rd gear.

Do you see something different?

[kennysabarese]

it must be the pink/black. i wish there was a way to test before cutting into the wire though

[snaponbob]

it must be the pink/black. i wish there was a way to test before cutting into the wire though

The pink black is not a signal line, it is voltage from the fuse panel. So, question - are we talking about a power source to the light assembly, or a tach signal to trigger the lights?

Here is the wiring diagram in MS Word. [attachment=1]

[kennysabarese]

sorry i misread your post!

ok then yeah i think i know the wire.

wish there was a way to test without tapping it

[kennysabarese]

BTW wiring diagram is excellent I have a 2007 but I'm sure it's the same

[kennysabarese]

Here it is for everyone as a PDF if they prefer

http://files.me.com/kennysabarese/1c3sfd

[snaponbob]

Here it is for everyone as a PDF if they prefer

http://files.me.com/kennysabarese/1c3sfd

Show off !!!!!!!!!!  JK.