My cell phone from T-Mobile is SAMSUNG's "SGH-E315"
I just tried to enter the Engineering-Mode of it.

Success entering:
*#06# Displays phones IMEI No.
*#9999# SW Version
*#8888# HW Version
*#0842# Vibrator
*#0289# Buzzer
*#0228# Battery Stat
*#0782# RTC Display (???)
*#0523# LCD Contrast
*#0778# Sim Size
*#0638# SIM network ID
*#0746# SSMS memory
*#4357# This screen (the actual help screen)
*#9324# Netmon (press the hangup key to exit)