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Pinpoint Test K: Lost Communication With Another Module

  1. Refer to MODULE COMMUNICATIONS NETWORK for schematic and connector information.

    Normal Operation and Fault Conditions 

    The GSM expects to receive network data from other modules on HS-CAN2. The GSM will set a DTC when it does not receive expected messages from another module. Other modules that require data from the suspect module may also set a lost communication DTC.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    GSM U0100:00 Lost Communication With ECM/PCM "A": No Sub Type Information For this vehicle, this DTC indicates the GSM did not receive some or all of an expected message from the SOBDMC over HS-CAN2.
    GSM U0121:00 Lost Communication With Anti-Lock Brake System (ABS) Control Module "A": No Sub Type Information This DTC indicates the GSM did not receive some or all of an expected message from the ABS module over HS-CAN2.
    GSM U0140:00 Lost Communication With Body Control Module: No Sub Type Information This DTC indicates the GSM did not receive some or all of an expected message from the BCM over HS-CAN2.
    GSM U0155:00 Lost Communication With Instrument Panel Cluster (IPC) Control Module: No Sub Type Information This DTC indicates the GSM did not receive some or all of an expected message from the IPC over HS-CAN2.
    GSM U0203:00 Lost Communication With "Door Control Module E": No Sub Type Information This DTC indicates the GSM did not receive some or all of an expected message from the DCME over HS-CAN2.

    Possible Sources 

    • Suspect module fault
    • Low system voltage
    • Incorrect PMI
    • High network traffic event
    • Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals

  2. K1 CHECK THE SUSPECT MODULE FOR DIAGNOSTIC TROUBLE CODES (DTCS)

    • Using a diagnostic scan tool, carry out a self-test on the suspect module.

    Are any diagnostic trouble codes (DTCs) present in the suspect module? 

    Yes  RESOLVE all diagnostic trouble codes (DTCs) in the suspect module first. REFER to the Master DTC Chart.
    No  If the module does not respond to the scan tool, RESOLVE the no communication concern for the suspect module. REFER to: Controller Area Network (CAN) Module Communications Network . Otherwise, GO to  K2

  3. K2 CHECK FOR LOST COMMUNICATION DIAGNOSTIC TROUBLE CODES (DTCS) IN OTHER MODULES

    • Using a diagnostic scan tool, retrieve all continuous memory diagnostic trouble codes (CMDTCs) from all modules.

    Is a lost communication DTC for the suspect module present in any other modules? 

    Yes  RESOLVE the intermittent no communication concern for the suspect module. REFER to: Controller Area Network (CAN) Module Communications Network .
    No  GO to  K3

  4. K3 CHECK ALL MODULES FOR LOW VOLTAGE DIAGNOSTIC TROUBLE CODES (DTCS)

    • Using a diagnostic scan tool, review all continuous memory diagnostic trouble codes (CMDTCs) in all modules.

    Is a low voltage DTC set in any module? 

    Yes  RESOLVE the vehicle voltage concern first. REFER to: Charging System .
    No  GO to  K4

  5. K4 CHECK FOR OTHER CAUSES OF COMMUNICATION CONCERNS

    NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.

    • Check the vehicle service history for recent service actions related to the suspect module or to the GSM. If recent service history is found:

      • verify correct replacement module was installed

        • HVBOM may be used to verify correct part application

      • verify the configuration of replacement module was correct

        • re-configure module using as-built data if prior configuration is suspect

      • verify the module was not obtained from a like vehicle and installed into customer vehicle

        • return the swapped module to source vehicle and obtain new replacement module

    Were any causes of a communication concern found in the vehicle service history? 

    Yes  PROGRAM or INSTALL a new module as necessary.
    No  GO to  K5

  6. K5 INSPECT ALL IN-LINE CAN (CONTROLLER AREA NETWORK) CONNECTORS

    • Ignition OFF.

    • Refer to MODULE COMMUNICATIONS NETWORK for schematic and connector information. Disconnect all in-line CAN connectors between the GSM and the suspect module.

    • Using a good light source, inspect all  disconnected electrical connectors for the following:

      • 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
      • spread terminals - install new terminals as necessary

    Are any connector or pin issues present? 

    Yes  REPAIR any connector or pin issues.
    No  Reconnect all electrical connectors. GO to  K6

  7. K6 ATTEMPT TO DUPLICATE THE DTC (DIAGNOSTIC TROUBLE CODE)

    NOTE: If a GSM self-test is carried out, the driver door must be fully closed. A false P166B DTC may set if the driver door is not fully closed during the self-test.

    • Using a diagnostic scan tool, clear all diagnostic trouble codes from the GSM.

    • Road test the vehicle.

    • Using a diagnostic scan tool, carry out the GSM self-test.

    Did the lost communication DTC return? 

    Yes  If lost communication diagnostic trouble codes (DTCs) related to the suspect module are now present in multiple other modules, GO to  K7 If the DTC returned in only the GSM, GO to  K8
    No  The system is operating correctly at this time. The concern may have been caused by a high network traffic event or an intermittent fault condition.

  8. K7 CHECK THE SUSPECT MODULE FOR CORRECT OPERATION

    • Ignition OFF.

    • Disconnect and inspect all suspect module connectors.

    • 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

    • Connect the suspect module connectors. Make sure they seat and latch correctly.

    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    Yes  CHECK for an applicable TSB, GSB, SSM, or FSA. If a service bulletin exists for this concern, discontinue this test and follow bulletin instructions. If none address this concern, INSTALL a new suspect module. For U0100:00, INSTALL a new SOBDMC. REFER to: Inverter System Controller [SOBDMC] . For U0121, INSTALL a new EBB. REFER to: Electric Brake Booster (EBB) . For U0140, INSTALL a new BCM. REFER to: Body Control Module (BCM) . For U0155, INSTALL a new IPC. REFER to: Instrument Panel Cluster (IPC) . For U0203, INSTALL a new DCME. REFER to: Front Door Latch .
    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.

  9. K8 CHECK THE GSM (GEAR SHIFT MODULE) HS-CAN2 (HIGH-SPEED CONTROLLER AREA NETWORK 2) CIRCUITS FOR AN OPEN

    • Ignition OFF.

    • Disconnect GSM C3245.

    • Disconnect GWM C2431A.

    • Inspect the connectors for damaged or pushed-out terminals.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-2
      GFD609551Courtesy of FORD MOTOR COMPANY
      		 C2431A-21
      C3245-3
      GFD609551Courtesy of FORD MOTOR COMPANY
      		 C2431A-8

    Is the resistance less than 3 ohms? 

    Yes  GO to  K9
    No  REPAIR the open circuit.

  10. K9 CHECK THE GSM (GEAR SHIFT MODULE) HS-CAN2 (HIGH-SPEED CONTROLLER AREA NETWORK 2) CIRCUITS FOR A SHORT TO GROUND

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-2
      GFD609551Courtesy of FORD MOTOR COMPANY
      		 Ground
      C3245-3
      GFD609551Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 1, 000 ohms? 

    Yes  GO to  K10
    No  REPAIR the short to ground.

  11. K10 CHECK FOR CORRECT GSM (GEAR SHIFT MODULE) OPERATION

    • Ignition OFF.

    • Disconnect and inspect the GSM 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

    • Connect the GSM connector. Make sure it seats and latches correctly.

    • Connect all other electrical connectors that were previously disconnected.

    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    Yes  CHECK for an applicable TSB, GSB, SSM, or FSA. If a service bulletin exists for this concern, discontinue this test and follow bulletin instructions. If none address this concern, INSTALL a new GSM. REFER to: Gear Shift Module (GSM) .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
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