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Discussion Starter · #1 · (Edited)
after having tranny problems my mechanic noticed that my crankshaft at the flex plate has six cracks on the outside edge..He thinks this is why my car shakes at idle and why my tranny pump broke twice?(according to them)...so I bought a used 4200 from a 2004 trailblazer(6k miles).....I am guessing I will need a case relearn and according to every source I have checked the engine is compatible any idea?
 

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Western Canada Chapter
2003
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after having tranny problems my mechanic noticed that my crankshaft at the flex plate has six cracks on the outside edge..He thinks this is why my car shakes at idle and why my tranny pump broke twice...so I bought a used 4200 from a 2004 trailblazer.....I am guessing I will need a case relearn and according to every source I have checked the engine is compatible any idea?
It is totally compatible. You will need to use your original PCM that was on your vehicle if you want it to start etc. OIC you have EFI live. As long as the 2004 PCM is not one of the bad ones.
 

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2003 gmc envoy_slt
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Just swap the PCM from your '03 to the new engine.You should be good to go. No CASE or security relearn needed. Check that :duh: : If you swap the Crank Angle Sensor From the '03 to the '04 engine and the PCM from the '03 to the '04, you won't need the relearns. The '03 PCM will already have the VIN and the C.A.S. programed in it.
 

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I think you're going to need to use the 04 PCM man, does your new motor have the AIR Injection pump above the exhaust manifold? The 03s dont so you will need at least to have your 03 PCM flashed (by GM, EFILive cant full flash the P10 f$*k) to an 04 OS to make it work. CASE can be done in EFILive, select 99-08 LS1 PCM under DVT in the scan tool, activate then press the CASE relearn. Rev to 4k until engine sputters, then release gas, let it return to idle, then shut off for like 15-30 sec.
 

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Discussion Starter · #5 ·
expain to me more about the AIR Injection pump ...this was to save the cat right? but cant it just be removed?...will the truck run at least with the 03 pcm?
 

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expain to me more about the AIR Injection pump ...this was to save the cat right? but cant it just be removed?...will the truck run at least with the 03 pcm?
Have your dealer flash an 04 OS into your 03 PCM, its the same PCM. AIR is for emissions junk, injects air into the exhaust right before the cat to help light-off when cold. You could remove it pretty easily I bet.
 

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Discussion Starter · #7 ·
engine is in and working with 2003 pcm ...it runs and is much smoother need a case relearn and I hope after that my p1481 will go away also....since I use that signal...runs so much smoother now and my ac still works the rear ac is acting up like it has been the last couple months...got some spare parts...intake manifold,,wire harness,,,whole 03 engine block with o2 sensor....I am not sure about the case relearn on efi live I cant rev past 3500 in neutral even if i change the settings
 

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Most newer cars won't let you rev them up when in neutral. Too easy to do a neutral drop and blow a tranny or loose control.
 

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Discussion Starter · #9 ·
yes it worked

had to get a new cam sensor....much better now no ces light..
 
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