Shift-up light on
Thread Starter
Drifting
Joined: Oct 2004
Posts: 1,976
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From: Patchogue NY
Shift-up light on
I posted this problem on the "tech" thread, but no one has come up with a solution yet. I swapped gears, from 2:59 to 3:54 in my 91 Coupe/auto, and at the same time I installed a B & M shifter improver kit, and an Electronic Ratio Adapter (ERA) to correct the speedometer readings. And, now this "shift-up" light comes on when the car reaches a speed of 50 mph and up. Is there some way of turning this light off? The cars an automatic, this light shouldn't be going off at all, right?
Joe B.
Joe B.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
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From: seattle WA
The up shift light is in all vettes that I'm aware of-wether stick or auto.Myself and another 87 vette owner had the same problem-but at less speed-the up shift light would come on. He thought he cured the problem when he changed fuel pumps, apparently his came back. I replaced my fuel pump and it hasn't been comming on all the time. The upshift light is for two things, 1, it lets you know when you're pressing the RPM level in a certain gear. 2, it's also for fuel economy-both are factory settings-irritating, but I wouldn't worry to much about it.
Thread Starter
Drifting
Joined: Oct 2004
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From: Patchogue NY
Thanks for the reply. It only just started coming on after I swapped gears, and added the B & M shifter kit, that't why I found it unusual. Do you think a custom tune could shut it off?
Joe B.
Joe B.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
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From: seattle WA
Really don't know if a custom tune would do it Joe, I do know there was another post on this same subject a week or so ago, you might check.It maybe a setting in the computer that now needs to be changed because of the change in gear ratios-but I'm not sure. How old is your fuel pump? My thoughts were-if the pump is getting weak the computer might be reading it as a fuel economy problem-thus causing the up shift light to come on. All I do know-is another member changed his fuel pump and thought his problem was corrected-but wasn't. With me, I changed the pump about six months ago-and it seems to have eliminated my problem with the light coming on.
Thread Starter
Drifting
Joined: Oct 2004
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From: Patchogue NY
Thnaks for the insight. Hell, I would venture to think that the fuel pump is original. I think I saw that post about fuel pump changing where one member resolved it. I guess that was you. I'll definately look into the fuel pump theory, is there a way of checking the efficeincy of a fuel pump?
Joe B.
Joe B.
Advanced
Joined: Jul 2004
Posts: 98
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From: Maple Grove Minnesota
Shift Light after gear change
I also changed gears, but from 3.07 to 3.73 and I experience the exact same thing. If you drive over 50 mph for a few minutes, light comes on and stays on until you slow down below 50. Only did it from the time I changed gears. I also know one other owner with the exact same problem, also only after the gear change. Both of us have had the problem for some time now (2+ years combined) and it doesn't appear to hurt anything. It is annoying as hell though! I also posted this maybe 6 months ago and no one seems to have a solution, but I would say it is definately not the fuel pump since these 3 cases all occurred only after the gear change. I also changed the speedo gears, but it didn't help.
Thread Starter
Drifting
Joined: Oct 2004
Posts: 1,976
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From: Patchogue NY
Yeah, that seems to be the consensus of the origin of the problem.
I'm having a custom chip made, and I'm going to see if the problem can be addressed through the chip. If it can, I'll post it.
Thanks for the reply.
Joe B.
I'm having a custom chip made, and I'm going to see if the problem can be addressed through the chip. If it can, I'll post it.
Thanks for the reply.
Joe B.
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Melting Slicks
Joined: Dec 2004
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From: Obama=death for America
Is there a bulb designated that only illuminates the "shift up" notification? If so, maybe removing it can cure this problem. Or is there one bulb that controls many functions, including this and by removing it, will cause the other functions to disappear as well? Just a thought.
Racer
Joined: Mar 2001
Posts: 312
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From: Mesa Az
shift up
I replaced my gears with 3.54's also and I am experiencing the same thing. I'm pretty sure it's because of the computer seeing high rev's at a lower speed.
Last edited by 88JDO; Feb 27, 2005 at 08:01 PM.
Race Director
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From: SCMR Rat Pack'r Charter Member..Great Bend KS
Originally Posted by rick lambert
The up shift light is in all vettes that I'm aware of-wether stick or auto.
Larry
code5coupe
Thread Starter
Drifting
Joined: Oct 2004
Posts: 1,976
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From: Patchogue NY
Originally Posted by rocco16
No up-shift light on my LT4....that I've ever seen.....
Larry
code5coupe
Larry
code5coupe
Joe B.
Pro
Joined: Jan 2005
Posts: 700
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this is what happens when you go messing with cars. Leave them alone they were designed right the first time around. Start messing with it and it will go downhill from there one thing leads to another just as you have found out. Changing the gears caused the sensor to detect the trans is running at to high of rpms.
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
Originally Posted by pionexxxx
this is what happens when you go messing with cars. Leave them alone they were designed right the first time around. Start messing with it and it will go downhill from there one thing leads to another just as you have found out. Changing the gears caused the sensor to detect the trans is running at to high of rpms.
Say again, except in English this time
Thread Starter
Drifting
Joined: Oct 2004
Posts: 1,976
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From: Patchogue NY
Originally Posted by pionexxxx
Let me put it in short redneck terms so you can understand, YALL are screwing your cars UP understand that? 
Joe B.
Team Owner
Joined: Dec 2000
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From: Phila., PA burbs
Originally Posted by pionexxxx
Let me put it in short redneck terms so you can understand, YALL are screwing your cars UP understand that?
Nope, still not getting it..............can you dumb it down a bit more for me
Drifting
Joined: Feb 2005
Posts: 1,592
Likes: 3
From: St Louis MO
I posted the same question in the "Tech" section a few days ago. I have an"87 Hbk, L98 w/auto trans and all stock. When cruising at 55 or above, the upshift light comes on. If I hard accelerate or slowdown to about 40, it goes off. No codes are thrown. The trans shifts at all correct points and the torque converter clutch kicks in and out at the proper times. You might want to look at some of the answers I got in Tech Section titled "Upshift Light on C4".