2002 PCM relearn won't stop flashing security
 

Hi All,

I have a 2002 Saturn SL2. I recently got a different PCM for it, as I was running an automatic PCM on my manual swap, I wanted to have the manual PCM in there to clear any emissions codes.

No matter what I do to try to marry the PCM to the BCM, the security light won't stop flashing. I have done numerous times the 3 x 10min procedure. Even waiting for 12mins each time, just to be sure, and it still won't learn.

Is there any special process for my vehicle? Would it make a difference that an aftermarket remote starter was installed? I don't believe any passlock bypass has been done on my vehicle, I did get a new key from the dealer a couple of years ago (they required my VIN) and it worked without issues starting the vehicle.

Any help would be greatly appreciated, and as much as a tech II would likely fix my problem, I don't have access to one (certainly not in my driveway, where my car currently is...).

Ivan

Both the PCM and BCM VIN #'s must match. Whatever is programmed in the PCM for a vin is not matching what the BCM is programmed with.

Dealer has to program this.

Interesting...I have read many reports from forums that folks have done exactly what I am trying to do, but not with my specific year (saturns became a rebadged gm in '03 and onwards...).

Does the vin not get updated in the more recent pcm's when a relearn is done?

VIN's aren't updated. In order for the BCM and PCM to talk to each other, both of the modules must have the same VIN programmed into each other. This is a security feature and why your security light is flashing.

So if I were to make the VIN's match, I can successfully do a passlock relearn?

The reason I ask is that I have an eeprom programmer, and I can access the eeprom directly...so if making the VIN's match is what I need to do, I'll start here.

Ivan

I don't think these types of PCM's have EEPROM's like the older ones do. But, if you can, take pictures, this I have to see.

How do I upload pictures here? Do I need to post to a third party site first, then link to it here?

Saturns are very finicky on there operating systems. Yes the Vin has to match both Modules. But once the Bcm has been programmed, its locked. Your better off buying another Bcm to match the other Pcm.

I'm not really looking to change the BCM...that's a pain in the ass to get to, and at the end of the day, my car would report a different VIN, which may cause me to fail the etests anyways...

There are surely ways to make this work from a dealer, but the dealers here don't seem to know anything about Saturns, so at this point unless anyone can suggest a way to force the relearn, I'm going to dive into hacking up the eeprom on the PCM.

You can't force a relearn unless both VINs are the same. And the EEPROM is not removable either.

You can put the original PCM back in, drive to the dealer and have them reprogram your CURRENT PCM with info that you need. Don't even bother with the oddball PCM.