Ok so here's my problem...

I have a T-56 Magnum in my 4.8l silverado 2wd RCSB. I got a code CS0055 which has to do with the rear speed sensor. Now ever since i did my install the speedometer has been WAAAY off. The service brake system light is on on the dash along with the parking brake light and ABS light. The ABS will kick on when u come to a stop at slow speeds everytime almost. Ive been told its because of the speed sensor in the transmission. Apparently the Magnum is more of a mechanical tranny and doesnt communicate with other sensors much which is why im having this problem (according to the guys and American Powertrain). They told me i have to block something out and change the pulses to around 12,000. I have no idea what the hell they are even talking about in general. Has anyone else run into this problem and if so any help/advice???

 

The pulses they are referring to is in the tune. You might want to speak to your tuner. I am sure your tuner should be able to correct the ratios to get everything functioning properly again.

 

The T56 has a 17T speed sensor reluctor wheel while the auto has a 40T. You need to go into the tune and change something, not sure what, so it knows how many teeth are on the wheel. It might be pulses per mile or something. Read through the T56 swap thread, it's in there.

 

Been waiting for Nelson Performance to call me back now for 2 days... lol

 

good luck, bunch of people had cruise control issues. I just put a 40 tooth reluctor in so i wouldnt have this problem.