This vehicle developed an intermittent start/stall problem. We originally thought it might be the BCM taking out the data bus. It happened when outside temps were near zero and applying heat to the BCM started the vehicle repeatedly. Replaced the BCM, problem came back a week later. Unplugged the data junction port to isolate the data lines and scoped each one to see all modules were "talking". Now the interesting part. The vehicle starts and stays running with the bus disconnected. Since then we have reconnected the bus and unplugged the SKIM module and the car is happy. Does anyone know if this is normal? Does the PCM consider no news is good news with respect to the SKIM module? In other words if it doesn't get a "bad key" signal it's happy? It doesn't actually need to get "good key" signal?

Michael Roy, Jr
Technician/Manager
Ford-Tel Service
Dearborn, Michigan, USA