Hello Dave: I will widen the speed range for you. 20 to 45 mph. When it happens the car acts and sound like a "jake Brake". The accelerator has always been engaged and the speed will suddenly drop to approximately 2 or 3 mph. Feathering the gas will have no effect other than to keep the car moving. Generally this will last for roughly 20 seconds and then go back to normal operation. No recent service other than oil change. The traction control light comes and goes and the event happens so fast and without a mechanical warning that I can not say if it is on prior to the event. No discernible vibration or pulsing in the brake pedal during normal driving.
I think we need to look a little further. This problem has always come on in dry conditions, no rain or puddles. The engine does not stall and tachometer is consistent with speed. The problem has been most associated with a gradual turn however it has also occurred on a straight run. Any other sensors we might need to look at?