NOKIA nk402 Secret Codes

Firmware Version:
*#0000#
*#51x0# or
*#9999#

View Serial No:
*#92772689#

Obtain IMEI (Serial) Code:
*#06#

Enhanced Full Rate (EFR):
*3370# to activate EFR.
#3370# to deactivate EFR

Half Rate Mode (HFR):
*4720# to activate HFR.
#4270# to deactivate HFR.

Default Security Code:
12345