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Discussion Starter #1
The cobalt automatic transmission is a 4T45E and is also found in the Cheby Malibu, how hard should it be for a Cobalt?
I know there are switches with their appropriate resistance (paddles), and another set of wires added to the clock spring. Would this be available in he Tech2 in the TCM setup?

There was a intresting article by the ARTA Tech department that covered tap shift features on the 4T65E & 4T45E.
 

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Discussion Starter #2
Now the following is my assumption and NOT based on any one document. If anyone knows better, please chime in, If it is anywhere close, chime in.
I think it would be a cool addition o add padel shift to Cobalts.

Now what i am trying to learn is the 04-08 Malibu tap shift.
Please correct my understanding.
BCM is programed to monitor the switches (gear shift & paddles) based on singles, instructs TCM to shift (up, down, or stay) or execute its normal programbased on shift cable, & PCM input.

The BCM is programed with a Tech2 but not as a Cobalt (product code A. I would correct this if I could see the old photobucket images)
Bcm need to be programed as a Malibu. What product code?

The TCM may need to be loaded with a Malibu 4T45E table values.

For better transmission, the valve body & solenoids may need to be upgraded to reduce shift time (transgo kit )

V=35
 

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Discussion Starter #3
Need GM schematics for the 2008-2009 automatic gear shift & steering wheel paddel shift?

I understand there is a switch and wire harness in center consol gear shift that goes to BCM. this is known to break and disable tap shift.
Coupled with steering wheel paddles & resistance that goes to bcm.
The steering wheel paddles work quite similar to radio & cruise buttons via different resistance. Reading them, by the BCM, is triggered by switch possition on center gear shift.

Now I dont know if the BCM tells the ECM / PCM to shift or communicates directly to the TCU to shift based upon input from steering wheel paddles & central console gear shift position
 

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It would be really interesting to see what you can come up with. I know a few other people have looked into it over the years but nothing ever really came of it. Paddle shifters would be sweet in my g5 once I get it built haha
 

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It can shift faster with some tuning but I have no problem rebuilding the trans haha every other system on the car is going to be freshly rebuilt anyways
 

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Discussion Starter #7
Far out rob.
Remember, i am NOT the all knowing on this subject, only integrating all of the comments from the other GM platforms that use the 4T45E and then adding my little knowledge on how GM engineers have been told what grandma and grandpa want in their Buick & Oldsmobile and all little johnny could afford was the old cheby. And he was trying to fit a 4 sp in and find all the brackets for the clutch peddle.
 

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Discussion Starter #8
Coupled with the schematics I just received along with the following article, I think I am close to trying to implement tap shift on a Cobalt.

I may need a malibu gear shift & tap shift enable switch or maybe just the switch.
Need to check some part numbers and compare Malibu gear shifter to Cobalt
Now the following article says the tap shift signal goes from the tap-shift paddle to the PCM. Yet, the scematics I have says it connects to the TCM.
http://www.atraonline.com/gears/2007/2007-10/2007_10_46.pdf
 

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I would think the diagram from the GM server is correct, why would you send a shift command to the ECM???
 

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Photobucket is getting pretty rediculous haha just the other day i was trying to use it it was asking if i wanted to pay for ad free and then proceeded to pop up 10 times more ads than it ever has
 

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There must be an other photo server .....
 

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Discussion Starter #14 (Edited)
There is other photo servers. In the mean time
For the tap shift enable there is one cable shown in the 2010 malibu.
Malibu steering wheel, with paddle shifters, is on the way in.
From gmpartswherehouse 2010 malibu center console
Harness - GM (20929193) item 14
And shift indicator Shift Indicator - GM (15946033) item 13
Thanks @Coby7
Second link. Tap-shift 07-up


---------- Post added at 06:34 PM ---------- Previous post was at 05:07 PM ----------

GM
STEERING/STEERING WHEEL & TRIM FOR 2010 CHEVROLET MALIBU
SELECT STEERING WHEEL & TRIM PART
8 15895323 / Switch Paddle Shift Right
9 15895322 / Switch Paddle Switch, LEFT

---------- Post added at 07:00 PM ---------- Previous post was at 06:34 PM ----------

Now I am a bit confused as to the output from tap switches (up & down)
One schematic 2007-up shows the output connects to the TCM pin 10 the other schematic 2004 show the connection to the PCM C1-45
 

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The 04 and the 07 up run completely different computers so the wiring is likely to be very different. You have to pick one and stick to it although I'd imagine the 07 up would be easier to get to work on our cars
 

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Your Cobalt has an ECM so I believe the signal should go to the TCM.
 

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Discussion Starter #18 (Edited)
Rob thanks your so right. Also since most cobalts were built after 2005 I would choose 2007 & up as Coby7 says Cobalts had PCMs in 05-06 and ECMs 07-10. The ECM integrated the ignition modules. So I do agree most strongly..

I spent the last several hr digging through GM's wiring part numbers and only find one harness going to the gearshift.
Right now, I AssUme it has the switch for tap shift enable when the shifter is placed in M for (P R N D M) or L for (P R N D L) as part of the illumination for the shifter ( shift indicator )

So a quick search on body wirign diagrams should confirm what GM part 20929193 haness item #14 connect to
Getting close. :)
And I will stick with 2007-2010 unless advised to limit it down to Just 2010.
 

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Bcm is different though, if you are going to be able to make it work you need to figure out what goes through the bcm and if it's something you can replicate if necessary.
 

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Discussion Starter #20 (Edited)
Right on Rob
Did you check the current replacement / interchange BCM part numbers?
I thought I checked and saw theye were interchangeable. Now granted there may be other relays that fit the BCM that Cobalt does not use. This could generate a new GM part number.


Im ready to go get a Malibu Automatic shifter and see if it will bolt down to a Cobalt ans see if the wire goes to the BCM
 
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