One problem related to transmission not go into gear has been reported for the 2003 BMW M3. The most recently reported issues are listed below.
1. When the temperature where I live reached around 95'f and above my transmission on my vehicle did not function properly. Would shift to neutral automatically resulting in loss of acceleration. I almost got rear ended by another vehicle. 2. Ever since the temperature got hot here in az, my transmission light has been on and the car keeps going into neutral while driving for about 6-15 seconds before re-engaging. It has happened everyday for the past 4 days, twice while making a left turn at an intersection, which is very dangerous. Many times while traveling straight. Consequences is that my safety is in danger the next time my car is not in gear and someone collides into my car. Very scared of my safety and my occupants. 3. Nothing has been done to correct this failure. BMW na knows of this issue, it is due to a faulty hydraulic pump temp sensor that was manufactured incorrectly resulting in the sensor reading an error in the temp and shutting down the smg transmission because it thinks that the hydraulic fluids are overheating(which is not the case). They want BMW M3 smg owners to replace the entire hydraulic sensor hcu unit. Which costs around $3000. 00 to replace in parts and labor. But the problem was the hcu's hydraulic fluid temperature sensor. It's a fairly cheap part to replace, but BMW is not admitting it. . Read more...