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Pinpoint Test O: P0887

  1. NOTE: The Secondary Inverter System Controller (S-ISC) is referred to as the SOBDMB (Secondary On-Board Diagnostic Control Module B) in the scan tool.

    Normal Operation and Fault Conditions 

    REFER to: Front Electric Drive Assembly - System Operation and Component Description .

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    SOBDMB P0887:00 TCM Power Relay Control Circuit High: No Sub Type Information This DTC sets when a short to power or open is detected on the relay control circuit.

    Possible Sources 

    • Wiring, terminals or connectors
    • BCM
    • Primary ISC (SOBDM-C) power relay control circuit

  2. O1 CHECK FOR LOW VOLTAGE BECM (BATTERY ENERGY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

    NOTE: Turn the ignition OFF for 5 minutes before carrying out the self-test or clearing DTCs.

    NOTE: DTC P0887 may set as a result of a low 12 volt battery concern or loose connections to the 12V battery or ground.
    NOTE: DTCs P0562 or U3003 may set in any module in addition to DTC P0887 set in the Secondary Inverter System Controller (S-ISC). Diagnose all other low 12V DTCs before entering this pinpoint test.
    NOTE: The Secondary ISC (S-ISC) is powered from the same relay that is controlled by the Primary ISC. DTC P0887 in the SOBDM-B can set due to P0887 in the SOBDM-C.

    • Ignition ON.

    • Using a diagnostic scan tool, retrieve all DTCs.

    Are there any DTCs related to the 12V battery present? 

    Yes  DIAGNOSE all 12V battery DTCs.
    No  GO to  O2

  3. O2 CHECK FOR PRIMARY INVERTER SYSTEM CONTROLLER (ISC) DIAGNOSTIC TROUBLE CODES (DTCS)

    NOTE: The key cycle is very important, the DTC will not clear unless a key cycle is completed.

    • Using a diagnostic scan tool, read the CMDTCs from the Primary Inverter System Controller (ISC).

    Is DTC P0887 present in the Primary Inverter System Controller (ISC)? 

    Yes  REFER to: Rear Electric Drive Assembly .
    No  GO to  O3

  4. O3 CHECK FOR LOW VOLTAGE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) DIAGNOSTIC TROUBLE CODES (DTCS)

    NOTE: The key cycle is very important, the DTC will not clear unless a key cycle is completed.

    • Ignition OFF.

    • Wait 5 minutes.

    • Ignition ON.

    • Using a diagnostic scan tool, clear the Secondary Inverter System Controller (S-ISC) DTCs.

    • Using a diagnostic scan tool, perform the Secondary Inverter System Controller (S-ISC) self-test.

    Is DTC P0887 present in the Secondary Inverter System Controller (S-ISC)? 

    Yes  GO to  O4
    No  The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

  5. O4 CHECK THE BATTERY AND CHARGING SYSTEM

    Are the battery and charging system voltages within specification? 

    Yes  GO to  O5
    No  REPAIR as necessary. REFER to: Battery
    Clear the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  6. O5 CHECK FOR CORRECT SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) OPERATION

    • Ignition OFF.

    • Disconnect and inspect all Secondary Inverter System Controller (S-ISC) 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

    • Reconnect the Secondary Inverter System Controller (S-ISC) connectors. Make sure they seat and latch correctly.

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

    Is the concern still present? 

    Yes  GO to  O6
    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.

  7. O6 INTERMITTENT CHECK

    • Access the SOBDMB and monitor the ECU_VPWR (V) PID

    • While observing, the PIDs carry out the following:

      • Carefully wiggle all accessible wiring and connectors associated with the Secondary Inverter System Controller (S-ISC)
      • Wiggle the Secondary Inverter System Controller (S-ISC) connectors and harnesses
      • Look for sudden changes in voltage when the harness and connectors are wiggled

    Are any concerns present? 

    Yes  REPAIR as necessary. CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test
    No  GO to  O7

  8. O7 CHECK THE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) VPWR CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Disconnect Secondary Inverter System Controller (S-ISC) C1456B.

    • Disconnect BJB C1035B.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C1458A-M1
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1035B-34

    Is the resistance less than 5 ohms? 

    Yes  GO to  O8
    No  With the aid of the OEM WIRING DIAGRAMS , REPAIR the open circuit.

  9. O8 CHECK THE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) VPWR CIRCUIT FOR A SHORT TO GROUND

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C1458A-M1
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 10K ohms? 

    Yes  GO to  O9
    No  With the aid of the OEM WIRING DIAGRAMS , REPAIR the short circuit.

  10. O9 CHECK THE SECONDARY INVERTER SYSTEM CONTROLLER (S-ISC) GROUND CIRCUITS

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C1458A-M4
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 Ground
      C1458A-L4
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance less than 3 ohms? 

    Yes  REFER to: Electrified Drivetrain Control
    Pinpoint Test Z.
    No  REPAIR ground circuit. CLEAR the DTCs and REPEAT the self-test.
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