[JimmyH]

This thread got me thinking:

http://www.cadillacforums.com/forums/cadillac-cts-forum-2003-through-2007/172576-odd-transmission-behavior-normal.html


For me, the manual shifting gate is worthless in this car. And I have had my dealer look at it, and they profess my transmission is working within specs.

Since the ECU for this car has long been cracked, would it be possible to reprogram the shifting pattern? Just when the shifter is manual shifting mode. I would like it to be able to upshift on demand, not wait until the computer says it is ok to upshift.

I am doing pretty good, getting 27-28 mpg on premium right now. But for the sake of hypermiling, I would like to be able to get it to upshift into the gear of my choosing, at the time of my choosing.

Anyone think this is possible?

 

[chevyhighperformance]

Right now HPTuners is the only game in town for programming the ecm. I'm not holding much hope for them to unlock the tcm to do as you want. I would like to control the tranny too.

 

[JimmyH]

guess I will have to keep dreaming then, or trade it for a standard

 

[Kingoftypos]

Jimmy, what were getting for mpg before the ECM crack? What did you buy and what did you do to the ECM? I haven't done anything with my ECM or any other in the past. I would really love to get more than 18 mpg on my 2.8 v6. I keep on telling myself that one of the reasons why I get such poor mpg, no matter what kind of car. Is because I live so close to work, around 3 to 3.5 miles one way. There have been times in the winter time that there isn't enough heat by the time j get home or to work, ha ha.

So I am looking into reprogram to get better gas mph, what do suggest?

KOT

 

[JimmyH]

I have not done anything to my ecm. I just meant that someone, long ago, figured out how to reprogram the computer. In contrast to the new CTS, which I believe, as yet, no one has cracked.

As for mileage, I keep telling you guys, it is not the car, it's the driver. If you need better techniques:

http://www.cleanmpg.com/

 

[BadAV]

From what I have been able to determine, based on HPTuners taking 4 credits, you can tune both the pcm and the transmission on the CTS. I haven't tried it yet as I've only had it for two weeks. I'm not sure I want to spend the equivalent of $200 worth of credits on my daily driver. I'm using the CTS to commute back & forth to work and, while I'm sure the performance and gas mileage could be enhanced (and most likely pay for the credits in relatively short order with the increased mileage), I just don't feel the need to do it at this point. It looks like I'm going to average 24-25 mpg in an 80/20 highway/city mix with a lot of heavy stop & go traffic.

I use HPTuners on my work/play vehicle, a Magnacharged 02 Avalanche with lots of performance mods (cold air induction, mid-length headers, Gibson cat-back, built tranny with shift kit, billet servos, 2600 stall converter, e-fans, 3" rear lowering springs, 20's, and I'm sure several other items I'm forgetting at this point). It's pushing 475 hp versus 285 stock and it's a blast to drive.