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2002 olds bravada
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5 Posts
Discussion Starter #1
looking for information on replacing a pcm. like do i have to reprogram the vin right away or have it flashed or can i just hook it up and then start the vehicle?
 

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2005 chevy
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6,469 Posts
looking for information on replacing a pcm. like do i have to reprogram the vin right away or have it flashed or can i just hook it up and then start the vehicle?
You have to have it programmed first, and then have the CASE relearn and possibly the security relearn procedures done before your truck will start up. You may want to read some of the threads under the PCMforLess forum for lots of good info.

Are you getting a tune, or did yours just go bad on you?
 

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Northwest Chapter
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11,824 Posts
Honestly as long as the PCM is from an 02-05 I6 truck, do the security relearn and have a CASE done (change the VIN if you want) and you're set. Word of caution, if its a PCM with an 04-05 OS then you will get a check engine light as your 02 doesnt have the AIR pump the 04+s do.
 

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2003 gmc envoy_slt
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7,190 Posts
I believe you will need to get the VIN changed.

If the new PCM is from a 2wd, it will cause CEL's on your AWD Bravada.

The VIN has all the info on your trucks options. :m2:
 

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2002 gmc envoy_slt
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The VIN doesn't need to be changed, mine was wrong for over a year.....the enhanced emissions inspections picked of the variance. The guy who came out to verify the scanned VIN at the state facility was like, yeah, its common if the PCM has been swapped out. Many times the dealer tech forgets to input the correct VIN when installing them. Unless you get a CEL, you may not need to have the CASE relearn performed even. Mine has never been done on the tuned PCM, runs great and no CEL.....other times it will set one off immediatley.

Mine was wrong of course, as I bought a used one from a yard and had it tuned by Lyndon up at Wester's Garage. Lyndon didn't realize it wasn't the original PCM and never check/corrected the VIN. - I did send it up for him to correct, which he did for the cost of postage.
 

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2004 chevy trailblazer_ls
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72 Posts
They are really easy to replace. It took me about 5 mins to unbolt and put my new tuned one in. PCM4Less took care of the VIN change. I did have to do the security procedure and the CASE relearn.
 

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2002 olds bravada
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Discussion Starter #7
You have to have it programmed first, and then have the CASE relearn and possibly the security relearn procedures done before your truck will start up. You may want to read some of the threads under the PCMforLess forum for lots of good info.

Are you getting a tune, or did yours just go bad on you?
Mine went completley dead wont start at all trouble shot everything possible
and you turn the key and nothing the starter wont turn over tested starter relay checked fuses even came on here and asked i did read messages from the very inteligent the roadie and all we could come up with is prolly the pcm
I wish it was just getting tuned :worried:
 

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2004 chevy trailblazer_ls
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Mine went completley dead wont start at all trouble shot everything possible
and you turn the key and nothing the starter wont turn over tested starter relay checked fuses even came on here and asked i did read messages from the very inteligent the roadie and all we could come up with is prolly the pcm
I wish it was just getting tuned :worried:
Why dont you? Get one from PCMforless and have the tune done and slap it in. It will cost the same or maybe even less than getting it from else where. Two birds one stone...
 

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2005 chevy
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Why dont you? Get one from PCMforless and have the tune done and slap it in. It will cost the same or maybe even less than getting it from else where. Two birds one stone...
:iagree: And your truck will run a lot better too! :yes:
 

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Northwest Chapter
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I believe you will need to get the VIN changed.

If the new PCM is from a 2wd, it will cause CEL's on your AWD Bravada.

The VIN has all the info on your trucks options. :m2:
VIN doesnt need to be changed, in our trucks it doesnt matter 2WD v 4WD v AWD, and VIN doesnt have all the options the RPO list does inside the glovebox.

Why dont you? Get one from PCMforless and have the tune done and slap it in. It will cost the same or maybe even less than getting it from else where. Two birds one stone...
Do it, I think they charge $159 for a new/used PCM tuned to your specs plus shipping. Much cheaper than a dealer.
 

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2003 gmc envoy_slt
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VIN doesnt need to be changed, in our trucks it doesnt matter 2WD v 4WD v AWD, and VIN doesnt have all the options the RPO list does inside the glovebox.

OK, good to know.

In that case check the TV marketplace. There are some listed there and one of them includes a tuned PCM.
 

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2004 chevy trailblazer_ls
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21 Posts
When you all say "get a PCM Tune from PCMforless", what do you mean? Do you mean that i can order a new PCM from PCMforless and have them tune it based on my VIN and all I need to do is replace my old one? Or is the PCM Tune an additional component that needs to be installed with my existing PCM?

the PCM is the computer, correct?

with the new PCM from PCMforless, will the performance be that much better?

I ask because I will be cleaning my throttle body tonight after the dealer wants to charge me $700 to replace my computer based on code P0606. If i do need a new computer, I will go through PCMforless, if that is an option.

thanks
 

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2005 chevy
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6,469 Posts
When you all say "get a PCM Tune from PCMforless", what do you mean? Do you mean that i can order a new PCM from PCMforless and have them tune it based on my VIN and all I need to do is replace my old one? Or is the PCM Tune an additional component that needs to be installed with my existing PCM?

the PCM is the computer, correct?

with the new PCM from PCMforless, will the performance be that much better?

I ask because I will be cleaning my throttle body tonight after the dealer wants to charge me $700 to replace my computer based on code P0606. If i do need a new computer, I will go through PCMforless, if that is an option.

thanks
A good starting point. Should answer a lot of your questions. :yes:

:coffee Sticky: PCMforless - FAQ & Information!
 

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Honestly as long as the PCM is from an 02-05 I6 truck, do the security relearn and have a CASE done (change the VIN if you want) and you're set. Word of caution, if its a PCM with an 04-05 OS then you will get a check engine light as your 02 doesnt have the AIR pump the 04+s do.
What is a CASE?
 

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Oh ok
I have ordered a pcm and gave them my vin# will i still need to do the CASE relearn?
Any recommendations on what kind of scanner to purchase that's not too expensive?
 

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2002 chevy trailblazer_lt
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1,054 Posts
Yes, if you are replacing the PCM then the Crank Angle relearn should be done. It will run without the relearn but it's ability to detect misfires from particular cylinders will be affected and it may set the check engine light.

For someone who os not seriously into doing their own repairs I would suggest calling around local repair shops to see what they charge to do it. Better equipped shops may have a capable scantool. If they don't know what a CASE or Cranshaft angle sensor variation relearn is then call another shop! As far as I know ot would a scantool capable of doing this will be in the neighborhood of $300 and up.
 

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looking for information on replacing a pcm. like do i have to reprogram the vin right away or have it flashed or can i just hook it up and then start the vehicle?
Hello
Might be better to have your original part repaired at UpFix - We save you money on rebuilding your failed electronics!

Here is the service link
 
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