DTC B2560: RKE Message Validation Error: Testing

Perform remote keyless entry diagnostic system check. See REMOTE KEYLESS ENTRY DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
If DTC B2560 sets with only one transmitter, go to next step. If DTC B2560 does not set with only one transmitter, go to step 4 .
Replace transmitter battery and reprogram transmitter. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article. After battery replacement and reprogramming transmitter, go to step 5 .
If DTC B2560 sets with both transmitters, go to step 6 .
Turn ignition off. Connect scan tool to DLC. Turn ignition on. Using scan tool, clear DTCs. Operate transmitter through all 4 button functions. Using scan tool, retrieve DTCs. If DTC B2560 resets, go to step 7 . If DTC B2560 does not reset, go to step 8 .
Turn ignition off. Connect scan tool to DLC. Turn ignition on. Using scan tool, reprogram both transmitters. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article. Operate both transmitters through all 4 button functions. Using scan tool, retrieve DTCs. If DTC B2560 resets with both transmitters, go to step 9 . If DTC B2560 does not reset with both transmitters, go to step 8 .
Replace transmitter and reprogram transmitter. See appropriate REMOTE KEYLESS ENTRY SYSTEMS article. After replacement and reprogramming transmitter, go to next step.
Verify remote keyless entry system operates properly by performing all 4 functions on transmitter. If remote keyless entry system operates properly, system is okay.
Replace BCM. See BODY CONTROL MODULE (BCM) under REMOVAL & INSTALLATION. Reprogram BCM. See PROGRAMMING . After replacement, go to step 8 .