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2005 PCM Calibration on a 2004

3737 Views 23 Replies 11 Participants Last post by  xtremesc2
Anyone remember seeing a thread about being able to load the 05 calibration onto an 04. I've been searching for the past hour. Wondering if it was maybe on another forum. Anyway, i know it' possible, I'm loaded it onto my 04 today, and the car feels a whole lot smoother, unsure of any power gains. Anyway everything runs fine except the speedo only operates between 0 and 20 and the odometer seems to have slowed down as well, not sure why this would happen consideringthe wheels, tires, gearing are the same between 04 and 05. Any thoughts?
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different cal is a different cal, im sure programming in the pcm is different in there somewhere.
how did you fool it to put a 05 cal on a 04?
We finally got an '05 on the lot at the dealership. Hooked that up to the Service Stall... when it came time for the download to take place... I moved the tech 2 to my car. I ended up switching it back to the 04 calibration.. it was interesting though... Speedo maxed out at 20.. odometer registered only 5 miles for every 15 driven (roughly).... Car drove amazing and the upshift lag I had disappeared... what i didnt like was my PCM was carrying around the 05's VIN number in memory... wouldn't work too well when it came time for emmissions testing. I guess maybe the '05 uses a different speedo set up.. I'd have to research it more.
yea probobly cant tell much without looking at the programming itself...
just curious, what dealer do you work at? I'm a tech at westbrook park in springfield..
Saturn of West Chester... I guess we're Winner cousins.
i go to Saturn of West Chester all the time for my stuff.....when im at school, i bought my car at Saturn of York tho.
The dealer has updated programs for the 04 that act more like the 05s. There's no trick to it. It's actually part of a TSB to upgrade the ECU on 04s to take care of the weird 1st gear bucking and other little nuisances.
cavingman said:
different cal is a different cal, im sure programming in the pcm is different in there somewhere.
how did you fool it to put a 05 cal on a 04?
And a different ECU is a different ECU. I have been letting an individual hook up to my car's ECU to get info for a product of his and have found out that the 04 ION Red Line has a Saturn specific Motorola unit in it that is different from the ECU in the '05 ION Red Line & Cobalts SS.

I have also had conversations with a tuner garage that is waiting on the software to be finished to re-program the Cobalt SS & 05 Red Line and was told that it was not for the '04 Red Line. It seems that this software company provides software for the C5 corvettes that help out a lot with their engines and the same should be true for the LSJ cars. I then asked a GM dealership service manager about buying an '05 ECU and throwing it into the '04 Red Line and he told me that it just isn't that simple, that our connectors could be different and the sensor parameters could be wired differently for the Motorola unit that would not be compatable with the different unit for the '05s. Sucks :(
Differences between the computers surprises me as the part number is identical for both years... wondering how you would differentiate model year if you had to order a new one. As far as the update being available for 2004, yes there is the same calibration everyone knows about by now, but I found the '05 update to improve it even further. Unfortunately there were issues and even if their weren't, I don't know enough about what changes it made to keep it installed for any extended period. Basically tried it to see if it would work.
Hey if i didn't have a conscience, or needed emissions testing, it'd bea nice way to keep the miles down ;)

XtremeSC2... I believe I looked at your car the day after I discovered my intercooler hose about to be sliced open.. get yours taken care of yet?
Blu_Redline said:
And a different ECU is a different ECU. I have been letting an individual hook up to my car's ECU to get info for a product of his and have found out that the 04 ION Red Line has a Saturn specific Motorola unit in it that is different from the ECU in the '05 ION Red Line & Cobalts SS.

I have also had conversations with a tuner garage that is waiting on the software to be finished to re-program the Cobalt SS & 05 Red Line and was told that it was not for the '04 Red Line. It seems that this software company provides software for the C5 corvettes that help out a lot with their engines and the same should be true for the LSJ cars. I then asked a GM dealership service manager about buying an '05 ECU and throwing it into the '04 Red Line and he told me that it just isn't that simple, that our connectors could be different and the sensor parameters could be wired differently for the Motorola unit that would not be compatable with the different unit for the '05s. Sucks :(

That seems to be very bad news.
any body have the tsb number so i can get that updatE
If your looking for a TSB on getting an 05 update on an 04.. there isn't one and technically it would void your warranty.. I just had the luxury of access to the needed equipment to test it out and change it back shortly after. If your looking for the normal 04 update, there are about a million threads that mention it... it dates back to January I believe. Good luck getting it without symptoms.
Blu_Redline said:
And a different ECU is a different ECU. I have been letting an individual hook up to my car's ECU to get info for a product of his and have found out that the 04 ION Red Line has a Saturn specific Motorola unit in it that is different from the ECU in the '05 ION Red Line & Cobalts SS.

I have also had conversations with a tuner garage that is waiting on the software to be finished to re-program the Cobalt SS & 05 Red Line and was told that it was not for the '04 Red Line. It seems that this software company provides software for the C5 corvettes that help out a lot with their engines and the same should be true for the LSJ cars. I then asked a GM dealership service manager about buying an '05 ECU and throwing it into the '04 Red Line and he told me that it just isn't that simple, that our connectors could be different and the sensor parameters could be wired differently for the Motorola unit that would not be compatable with the different unit for the '05s. Sucks :(
dazednconfused75 said:
That seems to be very bad news.
Don’t sweat it Dazed, this is mostly incorrect information IHMO
Went through all of this a few weeks back while doing some research on the ECM for this thread:
http://www.redlineforums.com/forums/showthread.php?t=1688

The 04 and 05 RedLine ECMs ARE identical, (exact same part number) but there are some wiring differences The wiring differences between the 04 and 05 Redlines are very minor and related to the optional Performance Pack (RPO:pDA/UXE) . It remains to be seen if the PP equipped vehicles are going to use a different calibration. (haven’t seen one yet) This will be important if anyone has plans to attempt to add the PP gage pod into an earlier RL.

The differences between the RedLine and the Cobalt ECMs are a bit more significant, but they ARE basically the same ECM (Motorola based PO5), with the exact same connectors and even share the large majority of wiring details. BUT they ARE a different part numbers than the Redlines and appear to maybe have some minor I/O differences, but the extent these differences affect the ECM internal hardware, has yet to be fully established.

The PRIMARY differences I found between the RedLine and SS ECMs were as follows:

1. The RedLine’s ECM is pure Class 2. It is connected to the Class 2 network ONLY, and the Redline does NOT utilize a High Speed GMLan. It’s networking topology is a mix of Class 2 and Low Speed (single wire) GMLan only.

2.The Cobalt DOES use a High Speed GMLan network and the ECM is on BOTH the Class 2 and High Speed GMLan networks. (*it also has a LS GMLan subnet)

Now it is my belief that the Redline ECM actually DOES have the capability to function in a HS GMLan, but as there is no HS GMLan network, these ECM terminals are just not connected. ALL of the other wiring is connected to the exact same terminals as the Redline and even share all of the circuit numbers.

But this networking difference appears to have 1 main significant difference and that’s in the way the cruise control is wired.


The Redlines steering wheel mounted cruise control switches are wired directly to the ECM so it can control the motorized throttle for cruise control operation.

On the Cobalt SS, the cruise control switches appear to be identical, BUT they are wired to the Body Control Module (BCM) and the switch data “shared” along the HS GMLan network to the ECM, which in turn control the throttle motor for cruise operation.

This is the only major difference I found. I also found the Cobalt SS shares the use of a single circuit for the boost pressure gage as the Redline’s Perf Pack BUT since it doesn’t use a “pod” with LED tach indicators, these ECM terminals are listed as “Not Used”

So what does this all really mean? Well 04 and 05 Redline owners can rest easy in that there is very very minor differences between their ECMs. And while yes they DO use different software files, keep in mind this is not unusual for GM to keep the calibration files for each model year totally separate, even when they maybe identical (other than filename). This is just the nature of the beast as the reprogramming software used is VIN based and therefore indexes/references the calibration files by model year FIRST, then platform, then engine RPO then optional RPOs such as tire size and presence of things such as the Perf Pack.

Not sure if this totally clarifies things for those of you interested in this sort of thing but…

Regards
WopOnTour
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SWCRedline said:
We finally got an '05 on the lot at the dealership. Hooked that up to the Service Stall... when it came time for the download to take place... I moved the tech 2 to my car. I ended up switching it back to the 04 calibration.. it was interesting though... Speedo maxed out at 20.. odometer registered only 5 miles for every 15 driven (roughly).... Car drove amazing and the upshift lag I had disappeared... what i didnt like was my PCM was carrying around the 05's VIN number in memory... wouldn't work too well when it came time for emmissions testing. I guess maybe the '05 uses a different speedo set up.. I'd have to research it more.
SWC
You're my kind of tech! A man willing to put his own ECM on the line in pursuit of knowledge- LOL Sweet!

It's not unusual for the calibration files (with different file numers) to utilize different offset and addressing values for various aspects of the calibration layout. GM does this to make it more difficult to "crack" the calibration software. The pass-through programming operation utilizes a "seed and key" security that "solves the puzzle" so everything goes to the correct memory locations when the calibration file is uploaded to the car.

But I must admit your results are intriguing. Since you seem hell bent on messing around…why don’t you try just using the "Replace and Reprogram" (as opposed to Reprogram Only) on YOUR car and then enter in the 05 VIN manually into TIS (just say NO when asked if the VIN is correct) This should load the 05 calibration correctly and insure things get arranged in memory properly using the correct “seed and key” sequence.
THEN see if the car STILL exhibits what you seen today.

PS> WTF did you run outta work today or something??? :D

Regards
WopOnTour
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Wow this is really exciting :) WE NEED TO RAISE THAT REV LIMITER!!!
*** maybe we can get some info together on the ecu?? do you work for a dealer?? can we somehow get a printed schematic?? i can call in a favor here but it would be cool to work with some here. i have extensive backround in electronics. i used to manufacture microchips at ibm from raw silicon and photoresist, i was a photolithography tech. used to repair the robots in the clean room. these ecu's are usually a cakewalk. not sure yet on the ion's but well soon find out.
I think I wet my self ::BLUSH:: LOL RAISE THE REV LIMITER!!! WE LOVE YOU GUYS !!
SWCRedline said:
Differences between the computers surprises me as the part number is identical for both years... wondering how you would differentiate model year if you had to order a new one. As far as the update being available for 2004, yes there is the same calibration everyone knows about by now, but I found the '05 update to improve it even further. Unfortunately there were issues and even if their weren't, I don't know enough about what changes it made to keep it installed for any extended period. Basically tried it to see if it would work.
Hey if i didn't have a conscience, or needed emissions testing, it'd bea nice way to keep the miles down ;)

XtremeSC2... I believe I looked at your car the day after I discovered my intercooler hose about to be sliced open.. get yours taken care of yet?


no i havent yet, when i took it to saturn of west chester to have it done, they found something minor wrong with it and ordered a part, and they were gonna do the tsb when they got the part in, but i was goin home for summer the next day, so im gonna have to find the time while im home now to go get it done. working 6:30-5:30 every single day doesnt help, haha.

where did u look at my car? u work at saturn of west chester?
I do indeed... I worked on your car that day. Great timing because needed another redline to compare that hose to my own and sure enough you had the same issue. I posted a thread last week asking people to check theirs out but got limited response.

***.. I initially tried manually entering an 05 VIN before we got the 05 on the lot... screen told me VINS did not match and would not let me proceed.
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