For a complete wiring diagram Refer to Section 8W.When Monitored:Continuously.Set Condition:Whenever the CAN INTERIOR BUS (+) or INTERIOR BUS (–) circuit is open, shorted to voltage or shorted to ground, this code will set.Possible CausesCAN INTERIOR BUS DTCs IN THE TOTALLY INTEGRATED POWER MODULE(D264) CAN INTERIOR BUS (–) CIRCUIT OPEN(D265) CAN INTERIOR BUS (+) CIRCUIT OPENAMPLIFIER1. TEST FOR INTERMITTENT CONDITIONTurn the ignition on.With the scan tool, record and erase DTCs.Cycle the ignition from on to off 3 times.Turn the ignition on.With the scan tool, read DTCs.Does the scan tool display: U0020-CAN INTERIOR BUS OFF PERFORMANCE?YesGo To 2NoThe conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.Perform BODY VERIFICATION TEST - VER 1.(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)2. CHECK FRONT CONTROL MODULE DTCsWith the scan tool, read Totally Integrated Power Module DTCs.Does the scan tool display any CAN INTERIOR BUS DTCs – ACTIVE?YesRefer to the symptom list for problems related to Communication in the ELECTRICAL.– ELECTRONIC CONTROL MODULES – ELECTRICAL DIAGNOSES section.NoGo to 33. CAN INTERIOR BUS (+) CIRCUIT OPENTurn the ignition off.Disconnect the Amplifier C1 harness connector.Disconnect the Totally Integrated Power Module C7 harness connector.Measure the resistance of the (D265) CAN INTERIOR BUS (+) circuit between the Totally Integrated Power module C7 harness connector and the Amplifier C1 harness connector.Is the resistance below 2.0 ohms?YesGo To 4Perform BODY VERIFICATION TEST - VER 1.(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)NoRepair the CAN INTERIOR BUS (+) circuit for an open.Perform BODY VERIFICATION TEST - VER 1.(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)4. CAN INTERIOR BUS (–) CIRCUIT OPENMeasure the resistance of the (D264) CAN INTERIOR BUS (–) circuit between the Totally Integrated Power Module C7 harness connector and the Amplifier C1 harness connector.Is the resistance below 2.0 ohms?YesReplace the Amplifier in accordance with the service information.Perform BODY VERIFICATION TEST - VER 1.(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)NoRepair the CAN INTERIOR BUS (–) circuit for an open.Perform BODY VERIFICATION TEST - VER 1.(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)