Shift Light Help

[ProperTuningOG]

I am trying to get the shift light to operate on a project we have. We are using the shift light to trigger kickdown on a TH400 through a relay. I can not get the ground trigger to work. I have a pin in 47 red and am testing now to see if it even triggers, it does not. The tune has a manual transmission and I thought I had everything set correctly. I have tried running it as a Y Body and GMT800, which is what it was originally. Any help would be awesome.

The goal is have it trigger off TPS only.

18008

[ProperTuningOG]

So I wonder if I am running into a wall here. I pulled the tune off the ECM with HPT and there are other shift light options available there like Min MAP, Max TPS, TPS Multi, Delay Time. Crap....... I own streams in EFI, since that is what I tune 99% of my stuff with. HPT hangs around on a few ECMs I need it for.

[ProperTuningOG]

New development. If I use B5801, Max RPM in All Gears, it works...... That's great for a shift light. I cant get it to trigger except on that setting.

It looks like I am hitting the MAX TPS table. In the segment I used is set to 0 in every cell...... Which we cant adjust....... Anyone have a CAX? :)

[ProperTuningOG]

Well, I bit the bullet and bought HP credits to test...... And nada. I can still only get it to work off the B5801 table. Any one know if this is rig/os specific?

[Taz]

Have never done this ... the tune attached below may not work ... the vehicle may have to be in motion (i.e. have an active VSS input) for this to operate.

[ProperTuningOG]

Dang, that's what I was afraid of.... I'll give it a shot and let you know

[Taz]

Good luck SkinnyPedal ...

[ProperTuningOG]

No go standing still.

[ProperTuningOG]

So speed does not trigger it either. Hooked a drill up to external seed sender. Tried many different speeds too.

Tried tuning the purge system to kick on 100% at high MAP, no luck there. Most I could get was 15 percent. Hmmmmmm, I need a dang high map or high tps trigger.

[5.7ute]

What OS are you using. (don't have efilive on this pc.) I cannot see any VSS modifiers on the memory map I have.

[ProperTuningOG]

12212156

[5.7ute]

There are quite a few parameters pertaining to the shift light. Making a cax file for them all will take me a while as I haven't played with them in ages.

[ProperTuningOG]

Do you think it can be made TPS controllable?

[Taz]

... I have a pin in 47 red ...

Checked on a few things ...

C2 (Red) pin 47 activates the "Skip Shift (1 - 4)" indicator lamp - but it would appear only for Corvettes with a manual transmission.

The "Shift" (or Upshift arrow lamp) is a Serial Data output to the IPC.

As the "Shift" (Upshift) lamp and the "Skip Shift" (CAGS) lamp could be concurrently enabled in a tune, I do not see how this single output (C2 pin 47) could be for both of these lamps - despite what the descriptions in B5816 and B5817 may suggest.

I would suggest wiring a contact activated switch to either the gas pedal, or throttle body, to activate the TH400 kick-down circuit.

Sorry that I cannot be of more assistance, but I have never experimented with this particular output.

[Taz]

There are quite a few parameters pertaining to the shift light. Making a cax file for them all will take me a while as I haven't played with them in ages.

Hello Mick,

I have access to every known parameter (and then some) in this OS. In the tune that I posted, I had manipulated most of these with respect to the Shift lamp.

If you were planning on building a *.cax file for your own use regarding these parameters - then by all means have a go.

If you were going to build a *.cax file solely to help out in this thread - it would probably be a waste of your time.


Cheers,
Taz

[ProperTuningOG]

Thanks for all the help!

[Taz]

You proposed in one of your posts that perhaps this function was vehicle / OS specific. That got me thinking ...

The original tune you posted was an LQ4 4L80 based tune, with manual transmission segments from a Corvette swapped in.

I checked a couple of actual manual transmission truck tunes ... seemed like the HD trucks (2500) did not have the "Shift" lamp enabled, while the light duty trucks (1500) did.

Try the attached tunes ... they are based on a 4.8L manual tune, which has now been highly modified (I imported most of your parameters).

[5.7ute]

Thanks for the input Taz.
Time is at a premium lately due to racing commitments, so it would be a while before I could get to build a cax anyway.
The descriptions I have for this parameter indicate that it wouldn't help the OP as they mostly are a "below this threshold" switch.

[ProperTuningOG]

Thanks again guys. I'll give the tunes a look once I get ve tuned tonight.

By switching to the 4.8 OS, wont that mess with the way the O2s are wired? I know the donor harness had isolated grounds and the O2 heater 12v came from them ecm.

[Taz]

Forgot to mention ... if either of those tunes actually activate a ground (for a relay or switch), they will only do so between 75% TPS and 100% TPS (which is when I thought you would want the kick-down to function).

[Taz]

...By switching to the 4.8 OS, wont that mess with the way the O2s are wired? I know the donor harness had isolated grounds and the O2 heater 12v came from them ecm ...

One thing at a time ... if the shift light output still does not work correctly, then we are beat ...

If it does, then the O2s are the next function to confirm ... in 2002 some 4.8L O2s were Case Ground and some were Isolated Ground ... good "big picture" thinking on your part ...

[ProperTuningOG]

I didn't make it to the shop last night in time to play with the two tunes. I have a 408 I have to tune today, so I'll get to test the shift light tomorrow. Thanks again for helping!

Putting in a switch for kick down isn't hard, I just thought I would try something different and easy.............

[ProperTuningOG]

Thanks for the effort guys but its a no go. Neither worked. I'm just going to put a switch in somewhere.