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-   -   Perform Shift and Normal Shift do nothing? (https://www.gmforum.com/1992-1999-91/perform-shift-normal-shift-do-nothing-253823/)

Hans 03-19-2007 05:53 AM

Perform Shift and Normal Shift do nothing?
 
I notice that I shift right around 5880-5920 in both perform shift and normal shift.

I take it this is not normal. Is there anything I can do to fix this? My only guess is that the transmission was replaced at some point in time with a junkyard trans from the wrong car.

I'm curious as to what others are running as far as shift points on their 97-99 cars.

BillBoost37 03-19-2007 07:29 AM

Your best fix is to realize that nothing is wrong. Search this topic out in the forums. Nearly everyone asks the same thing.

Maybe when they are new the transmissions feel different, however by the time we get them...you can't feel nada. ;) BTW..check at WOT or Bill W will post that right after my post :lol:

With a full Intense rebuild.. I feel a difference.
WillWren was able to see a couple hundred rpm difference on a logging scan tool.

The change is minor, if you can log data with your scantool, I'd suggest trying it both ways and comparing the data.

willwren 03-19-2007 07:54 AM

You must be WOT for the difference.

TrueWildMan 03-19-2007 09:51 AM

And, for the record, "perform" shift is actually normal operation, and "normal" shift is econo-shift. :P

BillBoost37 03-19-2007 11:22 AM


Originally Posted by TrueWildMan
And, for the record, "perform" shift is actually normal operation, and "normal" shift is econo-shift. :P

If you notice the 1-200 rpm difference, yes.

Until my rebuild..there was no noticable difference unless the scantool data for two runs was reviewed.

TrueWildMan 03-19-2007 11:24 AM


Originally Posted by BillBoost37

Originally Posted by TrueWildMan
And, for the record, "perform" shift is actually normal operation, and "normal" shift is econo-shift. :P

If you notice the 1-200 rpm difference, yes.

Until my rebuild..there was no noticable difference unless the scantool data for two runs was reviewed.

Yep! In my '93, I could tell the difference, it just shifted at a different RPM. But it was modded a bit. :)

Hans 03-19-2007 02:33 PM

i mean no difference the numbers you see are from my scantool.

sometimes its even closer, those were the max on the same flat road, at wot.

my numbers in normal shift: 5880, 5892, 5918.
my numbers in perform shift: 5876, 5897, 5920

I'M 100% SURE there is no difference, there is a 300 rpm difference or so on the 93 at least.

TrueWildMan 03-19-2007 07:11 PM


Originally Posted by Hans
i mean no difference the numbers you see are from my scantool.

sometimes its even closer, those were the max on the same flat road, at wot.

my numbers in normal shift: 5880, 5892, 5918.
my numbers in perform shift: 5876, 5897, 5920

I'M 100% SURE there is no difference, there is a 300 rpm difference or so on the 93 at least.

You have normal/performance switch in your '98?

BillBoost37 03-19-2007 07:13 PM

I'm pretty sure all Ei's came with the shifting mode buttons.

Maybe yours is broken? Either way, your shifts are where they should be.

TrueWildMan 03-19-2007 07:40 PM


Originally Posted by BillBoost37
I'm pretty sure all Ei's came with the shifting mode buttons.

Maybe yours is broken? Either way, your shifts are where they should be.

:grouchy:

Are you ribbing me? Trying to get me off my lame, disabled arse and go look? :P :lol:

I don't believe '00+ has that option anymore, if the '98 did.

http://members.cox.net/james.trojcak/Shifter.JPG
http://members.cox.net/james.trojcak/RightDash.JPG
http://members.cox.net/james.trojcak/MiddleDash.JPG
http://members.cox.net/james.trojcak/LeftDash.JPG


So, unless the Canucks had no use for 'em, I don't see one... :P

BillBoost37 03-19-2007 07:42 PM

:oops: Sorry..I thought we were talking about the 98's. 92-99's had them .

TrueWildMan 03-19-2007 07:49 PM


Originally Posted by BillBoost37
:oops: Sorry..I thought we were talking about the 98's. 92-99's had them .

D'oh! No, I'm sorry, I thought you were talking to me. LOL :oops: :oops:

I blame the pain-killers!! Again!!

BillBoost37 03-19-2007 07:52 PM

I'll blame the Goose.. ;)

Hans 03-19-2007 08:39 PM

so there is NOT supposed to be any difference on the 98s between the buttons?

willwren 03-19-2007 08:52 PM

There is.

Your PCM defaults to normal mode for a NA car in Performance mode.

Your PCM retards the shifts in economy mode by inducing a resistance (voltage divider circuit to drop the voltage from 5V at the PCM to 2.5V) in order to slightly retard the shift points for greater economy.

I have personally never seen a resistor short across the leads, so I'd say you have a short to ground holding that pin at a constant 5v and preventing the resistor from being introduced into the circuit.

Hans 03-19-2007 09:15 PM


Originally Posted by willwren
There is.

Your PCM defaults to normal mode for a NA car in Performance mode.

Your PCM retards the shifts in economy mode by inducing a resistance (voltage divider circuit to drop the voltage from 5V at the PCM to 2.5V) in order to slightly retard the shift points for greater economy.

I have personally never seen a resistor short across the leads, so I'd say you have a short to ground holding that pin at a constant 5v and preventing the resistor from being introduced into the circuit.

Where is this resistor you speak of? I'm happy to get the dmm with long leads to test while driving or whatever I need to do.


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