What are some of the BMW 318i e46 automatic transmission problems?

A common problem You might face on the BMW E46 318i is that the automatic transmission doesn't shift, or shifts erratically. This may be accompanied with the so called "safe mode", colloquially known as "limp mode", where the tranny won't shift at all to protect the engine. There'll often be a diagnostic troubleshooting code (DTC) on the iDrive display when this occurs. Indications of a transmission fault are the transmission stuck in gear, or it slipping from the gear, a malfunction message, or the engine revving up but then not actually shifting. You may also experience lag between going from first to second, or second to third. If You experience these issues, find a safe location and turn off the engine. Then, wait at least a minute and try to restart the vehicle. This sometimes can clear the error and allow You to shift normally, allowing You to drive Your BMW to a dealership. You can also try this hack: Turn on Your BMW, but don't start the engine. Press the gas pedal all the way to the floor and keep it down, and hold it there for 30 seconds. (Again, ignition on, engine off). After 30 seconds, turn off the ignition, and then try starting the vehicle and driving it normally.