I read about this on this site and I had it done yesterday. Took the dealer about 2 hrs but I didn't mind hanging out. After having the update the tranny shifts much quicker during normal driving and hard acceleration. I am very happy. This is the way it was supposed to come from the factory. :gears:

There is one weird thing though! My radar detector used to read a voltage average around 14, but now it reads 15.5 volts! :eek2: Anyone experience this? Is this also part of the update?

I'd love to know who is right on this. VMS says that the TCM part of that update is a typo. They use the GM site to do their updates on the tuned ECM's they sell. Sounds also like they have someone at GM they spoke to about it. The files from what I understood they were changing have nothing to do any of the table parameters in the ECM or TCM.

I'd love to know who is right on this. VMS says that the TCM part of that update is a typo. They use the GM site to do their updates on the tuned ECM's they sell. Sounds also like they have someone at GM they spoke to about it. The files from what I understood they were changing have nothing to do any of the table parameters in the ECM or TCM.

Correct, everything we've seen so far shows that the ECM update (which all of our customers already have) is for OBD compliance and DoD engagement feel. The TCM portion is the same calibration you already have however what some people could be feeling is the Transmission adaptives being reset after programming.

The latest listed calibration for the TCM is the one we've been working with and while there is some mention of the part #'s being the same (which we've never seen before in any vehicle) the CVN's would no longer match which would be a huge no no for the Calibration team so as of right now it appears there is no TCM update only ECM.

Correct, everything we've seen so far shows that the ECM update (which all of our customers already have) is for OBD compliance and DoD engagement feel. The TCM portion is the same calibration you already have however what some people could be feeling is the Transmission adaptives being reset after programming.

Can you post the actual TSB as a PDF or jpeg?

Then why do I notice a difference in the trans? Are they hiding something? Oh and the volts are normal now.

Then why do I notice a difference in the trans? Are they hiding something? Oh and the volts are normal now.

See post #3

10-4

Replied in this thread:
http://g8board.com/forums/showthread.php?t=2474

I'm not buying the idea that what we're feeling is just the adaptives being reset. This car has never shifted this firmly or so surely as it does now. The weird shifting was apparent from the 10mi mark when I first sat in it until now.

Now, whether it has to do with reflashing the TCM or the way the throttle is now more linear I can't really say. Maybe the less jumpy throttle is no longer artificially sending the system into a torque limiting/self-preservation mode. Just a thought. :dunno:

Guys:
I am used to 455 H.O. V8 engine with a good old Muncie M22 Rock Crusher 4-speed. Help me understand what the heck you guys are talking about...what are TCM, ECM, OBD, DoD engagement feel, CVN's, adaptives being reset, linear throttles....HELP!!

Would my dealer have done this update as part of the PDI (I picked mine up on April 30)?

BJ

Guys:
I am used to 455 H.O. V8 engine with a good old Muncie M22 Rock Crusher 4-speed. Help me understand what the heck you guys are talking about...what are TCM, ECM, OBD, DoD engagement feel, CVN's, adaptives being reset, linear throttles....HELP!!

Would my dealer have done this update as part of the PDI (I picked mine up on April 30)?

BJ

They SHOULD have, but not necessarily.

Post your VIN in this other thread and one of the folks there can tell you if your car was done or not: http://g8board.com/forums/showthread.php?t=2474

TCM is the brain of the electronic tranny.

The ECM is the brain of your engines electronic controls.

OBD is the onboard troubleshooting aid. It tells you when you have a problem and stores a code so whoever downloads it has a starting point to isolate it.

DoD is displacement on demand. It is a fuel saving measure so this powerful car doesn't drag down GM's fuel economy average TOO much and keeps them from having to pay a gas guzzler tax and pass that on to you. It does that by deactivating half of the cylinders during low load requirements. It's a tricky business to make that transition between 4 and 8 cylinder operation transparent to hyper-sensitive drivers.

CVN is a Calibration Verification Number. Basically it's one of the things that the technician can use to tell if there is a non-factory flash uploaded into the ECM.

Adaptives are your tranny's brain adapting to your driving style. If you are an aggressive driver it tried to be more aggressive...to a point, without jeopardizing itself too much. If you reflash them to factory specs it's like shutting off your computer without saving a word document. The program goes back to what it was before you started messing with it through your driving style.

Linear throttle is a description of how quickly your "drive-by-wire" throttle ramps up your throttle when you step on the gas. This car doesn't have a throttle cable like your 455 did. It senses how much you stepped on the gas and opens the throttle accordingly. The G8 came from the factory with a rather aggressive map for the throttle. If you stepped on it a little, you got quite a bit of throttle response...to the point of being a little jumpy off the line. Now it ramps up the throttle more in line with how far you're pressing on the throttle pedal, i.e. less jumpy.

Thanks lonewolfz28 - excellent responses. I think mine must have been corrected during PDI because I'm not getting any of the symptoms I've seen described. I'll post my VIN just to be sure.

BJ