I flashed a tune into my e38pcm a week ago and after doing so the speedo decided to stop working. It came up with the typical warnings on the dash..ie traction control and abs failure. These normally dissapear after a few key starts but I noticed the speedo wasnt working either. The warnings stopped but the speedo has since not worked. The traction control abs and speedo all not working. There is no signal coming from the e38 as I can not log it through the obd, it says 0 the whole time, and DFCO has stopped working as well as the coast down spark tables. It appears there is a signal to the pcm just none coming from it. I have checked all fuses and connections. I have done a full reflash with stock tune of the same os and disconnected the battery to reset the pcm with no luck. FYI I flash the pcm with ign off and let it count down the 15 seconds before starting.
It appears the pcm is damaged from the flash. Does anyone have any suggestions before I throw this thing in the garbage and buy another.
Joel