DTC B2402: STL unit comm.(system ID); DTC B2403: STL unit comm.(CRC); DTC B2404: STL unit comm.(function code); DTC B2405: STL unit comm.(rolling code); DTC B2406: STL unit comm.(PTC operate); DTC B2407: STL unit comm.(EEPROM); DTC B2408: STL unit comm.(solenoid): Notes

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

If DTC B2402, B2403, B2404, B2405, B2406, B2407, or B2408 is set, diagnose the CAN bus lines.
Whenever the steering lock unit is replaced, ensure that the communication circuit is normal.

Fig 1: Key Reminder Switch And KOS-ECU - Circuit Diagram
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.