Swapping A Pcm?

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Oct 26, 2006 | 09:20 AM

mph1972

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From: Newberry FL

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St. Jude Donor '07

Swapping A Pcm?

Is it possible to swap a PCM from a '99 and install it in a '99. I don't think it is possible without some tuning, but my buddy is curious.

Oct 26, 2006 | 11:38 AM

kromberg

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From: Lafayette Colorado

Both need to be the same transmission type first off. Both will need to have about the same mods done or else the tuning will be way off. If they are close, the PCM should handle the small differences.

Keith

Oct 26, 2006 | 12:19 PM

minytrker

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From: Burton TX

If the cars are the same you can but you will may have to get a crankre-learn done. You will get a ck engine light and a code if it needs to be done. I always recommend doing the procedure anytime you swap out motors or pcms. Any dealer or anyone with pretty much any tuning software can do it in in a few minutes.

Oct 26, 2006 | 12:57 PM

mph1972

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From: Newberry FL

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St. Jude Donor '07

Quote:

Originally Posted by minytrker

What exactly is a "crankre-learn?" I knew that some sort of tuning would probably need done, but I wasn't quite sure. I guess if you do this and one pcm is for a A4 with a 3:15 and the other A4 2:73 that will be needing adjusting.

Thanks for posting up, we were curious.

Oct 26, 2006 | 01:03 PM

kromberg

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From: Lafayette Colorado

Quote:

Originally Posted by mph1972

The crank relearn procedure entails the PCM making admustments based on the crank reluctor wheel, crank sensor, and I believe the cam sensor to determine the piston location. This is used for commanding injectors, spark plugs, etc. If you are chaning gears, you do not need to swap PCMs.

Keith

Oct 26, 2006 | 03:12 PM

Bill Curlee

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From: Anthony TX

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St. Jude Donor '08

I have a strange feeling that theres a LOT more to it than that!! I think the VIN's in the PCM and the BCM have to match also.

When you replace a BCM, you also need to program in any option that is on your car that isn't on a stock C5; like for instance F45 selective Ride, twilight sentential, ect...

There is a procedure that will allow you to accomplish the VIN match and it may be the CRANKRE learn but, I have never had to do it. I learn by the braille, skinned knuckles and blood method for most of the stuff that I get good at.

Oct 26, 2006 | 05:26 PM

minytrker

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From: Burton TX

I would make sure the OS systems are the same and tunes were the same also. You should also change the VIN in the new pcm. The crank re-learn can be done with tuning software or a tech II.

Oct 26, 2006 | 05:53 PM

mph1972

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From: Newberry FL

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St. Jude Donor '07

Quote:

Originally Posted by minytrker

I would make sure the OS systems are the same and tunes were the same also. You should also change the VIN in the new pcm. The crank re-learn can be done with tuning software or a tech II.

Appreciate it, this is not something I am doing to my car, just something someone was asking about that I work with. Sounds like it isn't to bad of a thing to do, but I will let him decide if he really wants to deal with it all. Nice to get an idea of what is behind all of this and I feel a little more knowledgeable on the whole thing. Thanks.