I am just finishing off a 3800SC swap using the engine, tranny and PCM from an 04 Impalla SS and I did turn off the pass key as far as I know it but the engine still does the fire up and die after a few seconds no matter what I do. I swapped the PCM out for a 2000 GTP one and it fires right up and runs fine engine wise so it has to be the PCM Am I missing some thing here with the 04 PCM pass key, any help is appreciated. Dan
Use your editor to open the program and confirm if the DTC's for passkey are not active. We use HP Tuners VCM tuning suite and its extremely user friendly. However, you could also do this if you have the DHP "powertuner" program that was sold by the now defunct Digital Horsepower company
------------------ 87GT - 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. 87GT - 3.4L Turbocharged engine, modified TH125H " I'M ON THE LOOSE WITHOUT THE JUICE "
There is two areas in the DHP program where pass key to my knowledge is turned off one is where you go into the security section and select false in this case making the VTD to be not present on car. Second is where you select for the PCM to ignore flash check sum then set the flash security to 255 to disable the security. This is all I have ever done with other swaps and every thing worked fine, that is why I am asking if there is some thing else I am missing here on the newer PCM's. Thanks Dan
Dan: Thats what I was referring to. On the GM Gen III PCM's you must turn off the DTC codes. Glad that you'vr got it solved.
------------------ 87GT - 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. 87GT - 3.4L Turbocharged engine, modified TH125H " I'M ON THE LOOSE WITHOUT THE JUICE "
That is what I though you were suggesting, I was just suprised that the codes had to be removed as well. Where with the older PCM's the codes have nothing to do with the actual function of the pass key. Dan
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06:14 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
No every thing came from an 04 if it had an older tranny I would have gone with a 99 or 2000 GTP set up. One thing good about the Impalla not getting the series III in 04 is this PCM would be good for those doing series III swaps using a series II throttle body and still using the tranny that came with the series III engine. Dan
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08:14 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
No every thing came from an 04 if it had an older tranny I would have gone with a 99 or 2000 GTP set up. One thing good about the Impalla not getting the series III in 04 is this PCM would be good for those doing series III swaps using a series II throttle body and still using the tranny that came with the series III engine. Dan
03 GTP code works just as well for the new trans.
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10:07 PM
Oct 6th, 2008
Dennis LaGrua Member
Posts: 16137 From: Hillsborough, NJ U.S.A. Registered: May 2000
I am just finishing off a 3800SC swap using the engine, tranny and PCM from an 04 Impalla SS and I did turn off the pass key as far as I know it but the engine still does the fire up and die after a few seconds no matter what I do. I swapped the PCM out for a 2000 GTP one and it fires right up and runs fine engine wise so it has to be the PCM Am I missing some thing here with the 04 PCM pass key, any help is appreciated. Dan
Dan: Just picked up on something else that you should be aware of. In 2003 the design of the 4T65eHD was changed to incorporate a new shifting technique. For instance the pressure control solenoids on the later transmissons operate differently. Look at the exploded wriring diagrams on the 2003 where the connections are made to the trans and you will also see different connections. As a result of these electrical and internal changes you will find that the 03-08 4T65eHD's ( even the std non-tap CA code trans) cannot be shifted by the earlier PCM's . I've done alot of research on this and believe this info to be correct. You will need to use a PCM from an 03-05 Impala or Bonneville 3800SC or a GTP 2003 unit. Since all these PCMs are essentially the same they will work. However, if you use the 04-07 GTPseries III PCM's those are ETC and you'll need to adapt the accelerator pedal module and harness shut off the fuel pump (and other codes) redo the fueling tables and change the wiring.
------------------ 87GT - 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite. 87GT - 3.4L Turbocharged engine, modified TH125H " I'M ON THE LOOSE WITHOUT THE JUICE "
