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Swapping Out ECMs

but im wondering if i need to have the same gears, 4 wheel drive. i know it will work but what requiremnts other than theft relearn do i need. or does it not matter
 
Not sure if 4x4 would make a diff but both should be for the same trany. If tire diameters are diff the speedo will be off. That can be adjusted.
 
I would say a computer off a 2wd truck would work as long as it has an automatic transmission. To my knowledge, nothing of the 4wd running gear is controlled by the computer.
 
There are some differences 2x4 vs 4x4 I don't know exactly what they are, but as an experiment I tried my Burb 2wd puter in the 4x4 Truck and got some codes saying it wasn't happy with that arrangement it ran okay but just wasn't exactly correct. I'd get as close to original configuration as I could

Best bet is to reflash yours as a F PCM, gains S to F PCM are okay you no longer have to deal with emissions junk & you get a little more fuel at WOT but F PCM performance overall is not that much different to a S PCM.
 
There may be other differences between 2x4 and 4x4.

The one I am aware of is that the transmission output speed sensor (TOSS) is of a different type, and sends a different type of signal to the ECM. The TOSS is located in the transfer case on the 4x4's.

This is the biggest bug in doing a mechanical IP swap to an OBD 1 truck, ala Bobbie Martin style.
 
There is a transfercase low range input on the ecm. It changes shift patterns. It will be indicated on a scan tool if in low range.
 
you could just swap chips couldnt you for obd1? my question is could i put a 1999 or 2000 computer that was 4x4 and an auto tranny in my truck since they had more power than the f trucks in 97 and 98
 
No,
It will not work, Passlock will be your problem. You need to stay with the 97 year computer if you want to swap.
If anybody say to do a relearn, it won't work because the PCM will looking for signal from the EVO/Passlock module, the 97 only came with the EVO module.
It won't work on the 97 because the ignition switch assy on the steering column does not have a sensor, the lock cylinder does not have a magnetic chip, the EVO module is not equipped with Passlock circuitry. EVO is the module that controls the variable power assisted steering.
 
Diesel 6.5,

PCM 97 & up will work once passlock is learned, both my 98s have passlock, I ran a 99 F PCM out of a 3:73 K2500 in my S 3:73 K1500 once I did the passlock relearn, ran 2 years that way before quality reflashes came out. My 98 C1500 passlock was taught to my K1500 truck, but missing the 4x4 speed inputs it ran goofy, plus the C1500 is 3:42, vs 3:73 in the K1500
 
TurbineDoc
Yes, 97 and up all used the same stock# computer but GM only installed the Passlock system in the 98 and up vehicles; as I explained before, the 97 column does not have the sensor, lock cylinder and the module to make the system work also the coding is not programmed into the 97 computer.
I am very familiar with the Passlock because I installed it in my 97 Tahoe. I swapped a complete 99 steering column and swapped the EVO module for the EVO/Passlock module from a donor vehicle and then fabricated a harness using the connector for the new EVO/passlock module and tying in the steering column bulkhead connector, PCM and the IP security light.
The reason why I did this was so I could swap in the stock F code 99 PCM.
If you installed the 98-99 computer into a 97 vehicle the PCM is going to be looking for a authorization signal from the EVO/Passlock module which is not there and so there is nothing to learn, the PCM will shut you down.
 
Thx for the translation, :thumbsup: missed it on 1st reading. :eek: wasn't sure of the full integration point of the TD setup looks like from your experience partially in effect in 97, so in this case if he can't find a 97 PCM, the best bet would be to go with a reflash and not have to worry about passlock issues

Another I forgot to mention I ran a 96 PCM K2500 also, but that one had a early mild reflash in it, one of the ones the Kennedy was testing back in the day wasn't much better than stock F, that was a Beta version, but did not have any theft lock issues with it. Which leaves me wondering if a 96 F PCM would work in a 97 ?
 
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