question about PCM swap

[Oddjob]

I have a used 94 sl2 car that I bought in Minnesota, and I didn't know that it was a california car. I have heard that you can swithc out the pcm's with a federal pcm, but my dealership said that the two pcms have diffrent connecters on them, and it would be impossible to switch them. I was wondering if anyone knows if this is true or how I could go about switching them if they are the same. Also if I can swich them does the pcm have to be reprogrammed at the dealership?

Thanks for any help.

Oddjob

[SCDYNE]

PCM's are all the same from Cali to Canada. The oonly difference is the fact that it's Auto or Manual.

What are you trying to accomplish?

[Oddjob]

There is a big diffrence. The California pcm has much stricter emmsions controls on them than the federal pcm. My friend has the same mods on his car, but has a federal pcm and blows my doors away. I believe that some of the diffrences are in fuel control and timing. I want to switch to the federal because I don't live in California so I don't need the extra emmsions controls.

Oddjob

[alkemyst]

I don't think the factory computer is controlling that....you may have a second cat or possibly some other restrictions added.

If you call Saturn you can see if they show a separate PCM part for the CA cars.

There are a ton of variables why one gets 'blown away' with the same mods.

Chris

[SCDYNE]

The answer is not in the configuration of the PCMs. There are no differences in that aspect of the PCM which would offer better or worse performance.

The answer here is for the question wanted to be asked not an answer that while correct would misslead. Yes they are numerically different, but it's not a factor here.

[wolfman]

Actually, have a look at your EGR valve. If it is the BLACK linear electronic EGR valve (Federal in 95' but California emmissions in 94') The dealer is correct. You "could" however swap in the federal PCM from a 95' SC/SL/SW 2 and it "should" plug right in and work fine. If the EGR valve is the vacuum operated "mushroom" shaped variety...the PCM from ANY 92-94 WILL plug right in to your harness. AND while the physical PCM UNITS themselves are the same in all 50 states and Canada, there ARE different calibration levels/EPROMM settings for California emmissions and "East coast" emmissions.

[amazinghl]

So... My car is from Idaho... but it's now in CA...

What do I have now??

[Oddjob]

Thanks, Wolfman. I will try that. I bought a 94 pcm federal and the dealer said that the connectors were diffrent, but I am going to get a 95 federal pcm like you suggested and give that a try. Do anyone know if after the new pcm is in place does it have to be reprogrammed by saturn or can it be reprogramed by just driving it around.

thanks,

Oddjob

[banjo]

what do you mean about "east cost emissions"? Is it all states on the east coast have california type restrictions?


Thanks,
Bill

[Oddjob]

From what I have heard there are only two diffrent pcm units, while they are the same on the outside the programing is diffrent. One is the federal and one is the California. Diffrent states may have stricter laws on car polluents, but as far as I know there are only those two.

Oddjob

[wingnut]

So is there a way you could find out using your VIN which PCM is on your car? Does this apply to OBDMII as well?

[ProDarwin]

Originally posted by banjo
what do you mean about "east cost emissions"? Is it all states on the east coast have california type restrictions?


Thanks,
Bill

I don't know if Saturn has different settings for them, but the east coast does have stricter emmissions than some central states, like the midwestern ones (Emissions?).

[Sbombin 4 life]

what about moded chips? anyone tried them?

[alkemyst]

What modded chips are available? JET so far has been the only one and it's basically the stock code relabeled. It's a decent code set though and for some people they get some improvements apparently, but my guess is it's just their minds fooling them having spent some bucks on something that does nothing.

The best 'chips' we have are the S-AFC and Venom 400. The former is much more versatile than the latter. People say the Venom does nothing, but some of the better drivers on the boards have had them and did get a slight improvement in quarter mile times....many don't drive well enough to notice the increase.

However, everyone that bought a Venom said for the the price N20 would be a better investment.

Used Venoms come up cheap sometimes, before I knew what it really was I had seen one at $75

[SCDYNE]

OK, funny thing...

There are some people working on hacking the Saturn PCM. Someone has even started selling a limiter modified PCM, which affectivly removes the limiters.

I'm involved in this process also and have been from the beginnning. I was the first person to actually look at the PCM, pull some code from it and eventually get the entire memory from it.

This was over two years ago now and I can honestly say that from the make up of the PCM and my expierence with speaking to people in the companies that make GM hacks There is no JET, HYPERCHIPS, DIABLO Sport, Superchips, etc, etc, etc hack for the Saturn PCM.

See these companies are just people with little to no knowledge of how PCMs work beyond what has been exposed by a select few individuals. They use that information to change the configurations of removeable EEPROMS and in some limited cases flash the EEPROM through the ALDL port.

Guess what? Saturn uses a unique PCM that's different than every other GM PCM on the market. They were programmed differently and configured differently. There is no removable EEPROM and the EEPROM that is on the PCM isn't the same as 99.9% of the other GM PCM's.
For the most part they are all the same in what they offe; Defaults, tables and some code. When this is the case it's VERY simple to look and see these tables to change.
That's not the case with the Saturn PCM.

So getting back to the original question: ANSWER:
"There are no differences in that aspect of the PCM which would offer better or worse performance."

As for other options:
Other than the limiter HACK offered by members of this community there isn't a OBDI hack yet.

I stress "YET" because there will be very soon.

And trust me when it's ready I'll be one of the first people to let everyone know it's the real deal.

I have spent the last few weeks almost 12 hours a day staring at dissassembly code from the PCM and walking through it.

All I can say is it's close to being really tested soon..