DTC B2721: Pass-Key(R) Detection Circuit (Out Of Range): Testing

If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, go to BCM DIAGNOSTIC SYSTEM CHECK .
Try each key provided with vehicle in ignition lock cylinder. Wait 3 minutes between each attempt to allow PASS-Key(R) timer sequence to reset. If one of the keys works, go to step 7). If no keys work, go to next step.
Using scan tool, check for DTCs B2722, B2723 or B2735. If any of these DTCs exist, go to appropriate DTC test. If none of these DTCs exist, go to next step.
Using Interrogator Adapter Harness (J-35628-A), perform lock cylinder test. See manufacturer's instructions. If problem is found, go to step 9). If no problem is found, go to next step.
Turn ignition off. Disconnect ignition lock cylinder connector C3. Turn ignition on. At BCM side of ignition lock cylinder connector C3, use DVOM to check voltage between terminals "A" (White/Black wire) and "B" (Purple/White wire). If about 5 volts exists, go to next step. If about 5 volts does not exist, go to step 8).
Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds and check for DTCs. If DTC B2721 is current, go to step 10). If DTC B2721 is not current, system is operating properly.
Replace malfunctioning ignition key. Go to step 11).
Check for intermittent problems in circuits No. 1073 (White/Black wire) and No. 1074 (Purple/White wire) between BCM and ignition switch. If no problem is found, go to step 10). If problem is found, repair as necessary. Go to step 11).
Replace ignition lock cylinder. See appropriate STEERING COLUMN article in STEERING section. Go to step 11).
Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.
Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM DIAGNOSTIC SYSTEM CHECK .