2003 Z06 1 to 4 shift?

[bitmunger]

Why would GM impose this restriction on a healthy engine. I have a couple of issues with my new C5 Z06. This one blows me away and is frustrating. Reference Document ID # 841088. According to this doc there are 2 reasons you will need to shift from 1st to 4th (no chance of grabbing 2nd or 3rd either). One reason I see as valid. The other; I totally do not understand! And a drum roll Please:
1. The engine coolant temp has exceeded 169degrees. This reason I understand.
2. you are going 15 to 19 mph and you are 21% throttle or less:confused
I think there is something wrong when you are forced or prohibited from grabbing all 6 gears, unless there is a service issue at hand.
Can anyone shed a little light on this mystery and provide a work-around?

 

[Lucy64]

From what I understand this was done to get around some Fed regs and to meet some mileage numbers. I have read in the Vette mags of something on the market you can install to get around this, and I am sure some of the C5 guys will be informing you of how and where. I did take a new C5 for a test drive (still won't part with my C2) and found if I just kept the revs up it didn't cause me any problems. I can see where it would be a pain.

 

[Edmond]

That 1 to 4 shift is for mileage purposes. If they didn't do that, I think it would warrant a gas guzzler tax or something like that.

I believe all 6 speed Corvette's are like that, but you can buy an aftermarket part to eliminate that. I think it's called the CAGS eliminator plug. I think some guys just unplug the CAGS and tape up the ends with electrical tape.

 

[MsSchroder]

Hello Bitmunger,
from another Atlanta z06 driver...
check out this thread about the 1st to 4th issue. There is a quick and easy fix (CAGS eliminator) if you can't live with being locked out of 2nd.

http://corvetteactioncenter.com/forums/showthread.php?s=&threadid=18849

Tammy

 

[Rob]

CAGS or Computer Aided Gear Selection has been around since the ZF 6-speed debuted on the 1989 Corvette. It was designed and implemented in order to improve fuel consumption and avoid the federal gas guzzler tax.

You can order a special CAGS plug seal kit from MidAmerica or Ecklers.

 

[Ctfoodguy2000]

I responded in the thread Tammy listed.

All the above answers are correct.

 

[Yeller Z06]

Note too that this "feature" is (was) present in the Camaro/Firebird product with six speed manual transmission. It is for gas mileage. It is a pain. Yank the plug.

Michael

 

[JBsC5]

I never run into activating this device so I have no problems with the general using it to meet Fuel economy standards set down by the federal government..

JB

 

[jak112460]

It's all about fuel economy. Have someone with a LS1 edit remove the skip shift protocol. I did it and it works great.

 

[MsSchroder]

jak112460:
Hello and welcome to the CAC.
can you tell me more about the LS1 edit? I have heard it mentioned before but have no idea what it is. I have never heard it mentioned in reference to cags elimination on the z06.

 

[jak112460]

The LS1 edit is basically a full cpu programmer. You can change timing and fuel curves on the go. It is very expensive and unless you have a dyno handy and have tuning experience I recommend you have a pro do it for you. When I had my supercharger installed at Cerra Racingthey did all the programming and testing on their dyno. I think just about every Corvette or LS1/LS6 tuner uses LS1 edit. Hope this helps.

 

[jak112460]

Sorry forgot to mention the skip shift. apparantly the LS1 edit can turn off the skip shift. Mine is turned off.

 

[Glenns]

Cost to eliminate 1 to 4 skip shift

1. LS1 Edit
2. Predator
3. CAGs plug
4. Drive it harder

 

[jak112460]

The cags plug is the least expensive choice.

 

[Edmond]

Yeah, but number 4 is the most fun!

 

[MsSchroder]

I broke down and bought the CAGS eliminator. I installed it today and it was easy. Here's how:
How To

Although this little annoyance only happened rarely for me, I discovered that disabling it completely has made me

 

[Ctfoodguy2000]

Nice job Tammy!!!

 

[vetahlk]

I am impressed!!!!
I purchased the CAGS elimimator for my 93 about 3 weeks ago and can't wait to use it. However, it has not been above freezing until today for about the entire month of Jan. Further the vette is put away until spring:cry so I'll have to wait until then to test it out. I am glad the job was simple.
John