Computer question

[oneluckypops]

Good Point, but 4 Wheel ABS wasn't even on the Radar in 91. At best you could get was Real Wheel ABS which worked off the differential rear carrier IIRC and not wheel sensors themselves. Also I think the Rear ABS was only OPTIONAL on the 88 New Body Style, not Squares. By 92, Rear Wheel ABS was required and then standard equipment. Again that's IIRC, it was 96 when they went 4 wheel ABS on the GM trucks. I think he's OK on that issue in this case.

I do beleive you recall correctly, I was just pointing it out on a what if scenario, because there seems to be more and more people intrested in doing the OBD II EFI systems, and its just food for thought.

 

[Jims86]

I do beleive you recall correctly, I was just pointing it out on a what if scenario, because there seems to be more and more people intrested in doing the OBD II EFI systems, and its just food for thought.

Yupper^^^^
Thats one of those things to be aware of if you are modifying a donor harness...some of those ABS systems have the same color coded wires as some of the EFI functions....dont want to cut the wrong ones.

 

[bucket]

not going to argue with you jim cause you know your ****. but i will add a little on the 2wd ecm being used in a 4wd.
Only probelm I could see is if the truck had 4 wheel ABS, which i know it doesn't but wanted to point it out anyway.

ECM receives a signal when 4wd is commanded then tells the ABS module of the change in driving style, if it didnt then fault codes would be stored for different wheel speeds from tire slipping.

Good Point, but 4 Wheel ABS wasn't even on the Radar in 91. At best you could get was Real Wheel ABS which worked off the differential rear carrier IIRC and not wheel sensors themselves. Also I think the Rear ABS was only OPTIONAL on the 88 New Body Style, not Squares. By 92, Rear Wheel ABS was required and then standard equipment. Again that's IIRC, it was 96 when they went 4 wheel ABS on the GM trucks. I think he's OK on that issue in this case.

'91 Squares had rear wheel ABS. Not sure if it was standard or optional, but my buddy's BASE model '91 K5 had rear wheel ABS.

It worked off the trans mounted VSS, not the rear axle housing. I can see where there would be a difference between 2wd/4x4. IIRC the ABS was turned off when shifted to 4wd, or maybe just 4lo.