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DTC U2107: Lost Communication With BCM

  1. Perform VEHICLE ON-BOARD DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. If vehicle on-board diagnostic system check has been performed, go to next step.
  2. Using scan tool, attempt to establish communication with BCM. If scan tool does not communicate with BCM, perform VEHICLE ON-BOARD DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. If scan tool communicates with BCM, go to next step.
  3. Turn ignition off for 10 seconds. Turn ignition on. Using scan tool, observe scan tool display for DTC U2107 in TCM. If scan tool displays LAST TEST FAILED for DTC U2107 for TCM, go to next step. If scan tool does not display LAST TEST FAILED for DTC U2107 for TCM, problem is intermittent. Check all connections and CAN link circuits between BCM and TCM for an open. See DATA LINK CONNECTORS article in WIRING DIAGRAMS.
  4. If vehicle on-board diagnostic system check has been performed, no "U" type DTCs should be set in BCM. If ECM and TCM set DTC U2107, BCM is unable to communicate on CAN link. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Retest operation.
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