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DTC B0603: BCM Internal Memory Malfunction (Write Error): Testing

  1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK  .
  2. Using scan tool, clear BCM DTCs. See BCM DTC DEFINITIONS  under SELF-DIAGNOSTIC SYSTEM. Turn ignition switch to LOCK position. Wait 10 seconds. Turn ignition switch to RUN position. Using scan tool, check for codes. If DTC B0603 is set, go to next step. If DTC B0603 is not set, go to step 4).
  3. Replace BCM. See REMOVAL & INSTALLATION  . Reprogram BCM. See BCM PROGRAMMING  . Go to step 5).
  4. System is operating properly at this time. See DIAGNOSTIC AIDS.
  5. Turn ignition switch to LOCK position. Reinstall all components and connectors. Turn ignition switch to RUN position. Using scan tool, clear DTCs. Check for DTCs. If any DTCs are current, perform BCM DIAGNOSTIC SYSTEM CHECK  . If no DTCs are current, system is operating properly.
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