This suburban had a different tranny control module and a 502 ram jet with 1 ton rear. Problem, cruise and ABS worked fine until batteries went bad this winter (11 years old optimas). After replacing them at 16-18 mph I get the orange anti lock brake warning light and sometimes I get the red brake warning light but not always. And the cruise stopped working. Fuses good, I thought I had it narrowed down the the speed sensor in the trans that I read controls the rear ABS and has input over the cruise. Big suprise when I went to replace it, it is unplugged and has been for years, probably as long as the trans module UG. And come to think of it I don't think the rear ABS ever worked but the front did and so did the cruise and it never had warning lights. Any ideas are grestly appreciated, seems it should be something that is common to both problems.

 

One thing to add, when the batteries went bad the battery guy said one had shorted out internal. I am wondering if the ECM is fried, Seems odd I would lose cruise and ABS without it being some common component. Any ideas are welcome and if your wondering how it drives, yes it hauls @**, tows like a MF as well. Loves the gas, gets 8 towing 9.8 highway.