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Pinpoint Test U: The Radio Transceiver Module (RTM) Does Not Respond To The Diagnostic Scan Tool

  1. Refer to Module Communications Network for schematic and connector information. Refer to Tire Pressure Monitor System for schematic and connector information.

    Normal Operation and Fault Conditions 

    The RTM communicates on the MS-CAN.

    Possible Sources 

    • Fuse
    • Wiring, terminals and connector
    • RTM

    Visual Inspection and Pre-checks 

    • Verify BCM fuse 32 (10A) is OK.

  2. U1 CHECK THE RTM (RADIO TRANSCEIVER MODULE) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Disconnect: RTM C9026.

    • Ignition ON.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C9026-6
      GFD429293Courtesy of FORD MOTOR COMPANY
      Ground

    Is the voltage greater than 11 volts? 

    Yes  GO to  U2
    No  VERIFY the BCM fuse 32 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short.
  3. U2 CHECK THE RTM (RADIO TRANSCEIVER MODULE) GROUND CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C9026-1
      GFD429294Courtesy of FORD MOTOR COMPANY
      Ground

    Is the resistance less than 3 ohms? 

    Yes  GO to  U3
    No  REPAIR the circuit.
  4. U3 CHECK THE MS-CAN (MEDIUM SPEED-CONTROLLER AREA NETWORK) CIRCUITS BETWEEN THE RTM (RADIO TRANSCEIVER MODULE) AND THE GWM (GATEWAY MODULE A) FOR AN OPEN

    • Disconnect GWM C2431.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C9026-4
      GFD429294Courtesy of FORD MOTOR COMPANY
      C2431-23
      C9026-3
      GFD429294Courtesy of FORD MOTOR COMPANY
      C2431-22

    Are the resistances less than 3 ohms? 

    Yes  CONNECT the GWM, GO to  U4
    No  REPAIR the circuit in question.
  5. U4 CHECK FOR CORRECT RTM (RADIO TRANSCEIVER MODULE) OPERATION

    • Ignition OFF.

    • Disconnect and inspect all the RTM connector.

    • Repair:

      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary

    • Reconnect the RTM connector. Make sure it seats and latches correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable service articles: TSB, General Service Bulletin (GSB), SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new RTM. REFER to: Radio Transceiver Module (RTM)
    No  The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.