Hi all
i’m building a hotrod with a 4.3 v6 from a 99 Blazer, but I didn’t get the BCM or key from the donor vehicle, so as I understand it the VCM won’t let the engine run, since it needs to talk to the BCM and key to not be immobilised.
i have read that swapping the 99 VCM for a 96/97 will Let the motor run since these years parts don’t have the immobiliser function.
is this true?

Also, looking at the wiring diagrams, it looks like the 97 has four oxygen sensors, one for each bank, and one before and one after the catalytic converter. If that’s the case will the engine run without the cat oxygen sensors?

One last question.... im converting from a four wheel drive to two wheel drive box, are there any electronic issues there?
Thanks in anticipation of help!

 

Most tuners should be able to remove the VAT locks (Vehicle Anti-Theft) from the PCM with no trouble at all. Then the PCM will not even look for a VIN match from the BCM, and will work without a BCM even hooked up (there is no immobilizer built into the key on these either, so you don't have to worry about that). The VAT removal shouldn't cost much at all, but you'll want to give the tuner any numbers on your PCM first to make sure that he can do it. I'm not sure what kind of computer the 99 uses, but I know that I can do it to the PCM that's in my 04 (it uses the standard 411 style PCM that hot-rodders like to use because of it's ability to run the LS engines)

If you're going to use a factory computer like this, you will need the two upstream O2 sensors right after the manifolds. The others further down the exhaust are just for cat converter function check. Without those in place it'll throw a trouble code (which can also be tuned out of the PCM), but it'll otherwise run just fine without them.

There shouldn't be any electrical differences between the engine running part when concerned with 2wd vs 4x4. There are some transmission shift tables that change when the PCM seems 4 low selected, but if you're using the PCM on a 2wd it'll never see that 4 low signal, so it doesn't really matter.

 

Thanks for your advice.
which tuner would you recommend ?

 

There are a ton online, even through eBay. They usually charge a flat rate. You tell them the computer you have, what engine you're running, and what changes you want done to the computer. Ship them your computer, and they flash it and ship it back.

Post a picture of the computer you have. If it's the same style as mine, I would be willing to give it a shot.

 

Interesting!
I'll get a picture of the computer, and its part number and come back to you.
Thanks again for your input.

 

Hi
Finally got the ECU out and here's the pictures of it.
The part number is 16263494.
Do you think you can reprogram it?