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Discussion Starter · #1 ·
I switched out the PCM in my 2007 300c SRT8 and now I'm having a weird issue with the auto up-shift :(

WOT auto up-shift from 1st-to-2nd: the engine cuts-off at rev limit and then shifts into 2nd gear and keeps going(feels like the car dies between 1st and 2nd gear)

Same WOT auto up-shift from 2nd-to-3rd gear: feels like the engine cuts-off at rev limiter, then shifts into 3rd gear and keeps going

The tune on the PCM is stock(latest version that is available was flashed on my PCM)

Is this normal?
 

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Sounds to me like there is a conflict between the PCM Rev Limiter and TCM Wide Open Throttle shift points. You'll either have to raise the rev limiter or lower the WOT up shift RPM. I usually keep about 500-600 RPM difference between mine......Rev Limiter set higher than desired WOT up shift RPM. The only time I've hit the Rev Limiter is once when I forgot I was in autostick mode and it didn't shift because I thought I was in auto mode.
 

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Discussion Starter · #6 ·
i'm coming to the same conclusion that the PCM and TCM aren't best friends

I'm knee deep in HP tuners tutorials, don't wanna blow anything up

Thanks!!!
 

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Also, that's what the Rev Limiter is suppose to do.....cut the fuel at the RPM that it set to.

Back both the PCM and TCM files up by doing a read vehicle flash. Go into the file, go to fuel and then fuel cut off. Set your RPM 500-600 RPM higher than your WOT shift points. Do a "Save As" and call the file something like, Stock (or whatever you called the original copied file) Tune Raised Rev Limiter to 6XXX RPM. IIRC, mine are at 6500 or 6600 RPM and WOT shift points are at 6000 RPM.
 

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Discussion Starter · #8 ·
Also, that's what the Rev Limiter is suppose to do.....cut the fuel at the RPM that it set to.

Back both the PCM and TCM files up by doing a read vehicle flash. Go into the file, go to fuel and then fuel cut off. Set your RPM 500-600 RPM higher than your WOT shift points. Do a "Save As" and call the file something like, Stock (or whatever you called the original copied file) Tune Raised Rev Limiter to 6XXX RPM. IIRC, mine are at 6500 or 6600 RPM and WOT shift points are at 6000 RPM.
sweet thanks a ton
 

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i'm coming to the same conclusion that the PCM and TCM aren't best friends

I'm knee deep in HP tuners tutorials, don't wanna blow anything up

Thanks!!!
So, you have an HP Tuner? If so, did you get the Professional Version or the other one? Also, have you done a "read flash" on yous and saved it to its own directory on your computer? Have you used credits to license your vehicle and files?
 

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Discussion Starter · #10 ·
So, you have an HP Tuner? If so, did you get the Professional Version or the other one? Also, have you done a "read flash" on yous and saved it to its own directory on your computer? Have you used credits to license your vehicle and files?
I found a dyno shop around here that tunes :)

I will have them tune as I'm getting a 426 stroker, heads & big cam and will either way need a professional tune

I can have the tuners fix my TCM issues and also tune the engine :)
 
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