This is a Toyota ECM computer electrical malfunction. I was waiting in my 2007 Toyota Fj cruiser at a traffic stop for the light to change from red to green. At this time, I felt a hard "bump" as if another car had rear-ended my fj. There was this real hard "thump." The fj had shifted gears on its own while at a complete stop. Either the transfer case differential and/or the electrical rear differential locked up. Both my hands were on the steering wheel and my right foot was on the brake at the time. There is no driver's side floor mat. The fj got a strong grip on the road and it lurched forward. There was a lot of extra power and a lot more traction than in the normal "D" mode for driving on dry pavement. Instinctively, I pressed down harder on the brake in order to keep the fj from moving into the intersection. Two seconds later, there was another "thump" and the fj shifted back into the normal road gear "D." I believe what happened is that the ECM computer sent a malfunctioning signal and locked up one or both of the differentials. This happened with an automatic transmission on dry pavement and stop when there was no driver command to shift gears. The sensation I felt is similar to using my fj for off-road driving and shifting into 4WD "low, " but this was much more severe. My concern is that the ECM computer might malfunction highway speeds of 70 mph. It could send a similar command to lock up either the transfer case differential or electric rear differential. If this happens, the fj becomes a 5,000 lb. Flying missile, basically out of control. I would not be able to steer the fj or to navigate turns properly. It would become a danger not only to myself, but to all other cars in the immediate vicinity. This is the first time it happened. Something is dangerously wrong with Toyota's ECM computer system in the Fj cruiser.

- Ridgecrest, CA, USA