I picked up an OBD2 adapter to stream data to the smarty phone. The adapter works great on my bone stock 01 2500hd 6.0 but on my efi live tuned 02 2500hd 6.0, I can not get it to connect to the ecu. I've also tried this reader and again, it powers up but wont connect. I've checked the CIGAR fuse and its good along with power at the DLC.
FWIW, I did not tune the ECU my self. I had a reputable tuner tune it.
Any thoughts or suggestions? Is the ECU locekd?
Thanks