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Pinpoint Test X: P0A4D

  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 P0A4D:00 Generator Position Sensor Circuit Low: No Sub Type Information This DTC sets when an error is detected in the resolver excitation circuit.

    Possible Sources 

    • Wiring, terminals or connectors
    • Front electric drive assembly

  2. X1 CHECK THE RESOLVER HARNESS CIRCUITS FOR AN OPEN

    NOTE: Wiring overlays or repinning of circuits are NOT appropriate due to risk of hardware damage.

    • Disconnect Secondary Inverter System Controller (S-ISC) C1458A.

    • Disconnect Front electic drive assembly C1280.

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      C1280-9
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1458A-A1
      C1280-8
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1458A-B1

    Is the resistance less than 3 ohms? 

    Yes  GO to  X2
    No  REPLACE the harness, CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  3. X2 CHECK THE RESOLVER HARNESS CIRCUITS FOR A SHORT TOGETHER

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      C1280-9
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1280-All pins
      C1280-8
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1280-All pins

    Is the resistance greater than 10K ohms? 

    Yes  GO to  X3
    No  REPLACE the harness, CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  4. X3 CHECK THE RESOLVER HARNESS CIRCUITS FOR A SHORT TO GROUND

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      C1280-9
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 Ground
      C1280-8
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 10K ohms? 

    Yes  GO to  X4
    No  REPLACE the harness, CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  5. X4 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TO VOLTAGE

    • Ignition ON.

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      C1280-9
      GFD609107Courtesy of FORD MOTOR COMPANY
      		 Ground
      C1280-8
      GFD609107Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is any voltage present? 

    Yes  REPLACE the harness, CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.
    No  GO to  X5

  6. X5 CHECK THE GENERATOR RESOLVER CIRCUITS FOR A SHORT TO THE EXTERNAL CABLE SHIELD

    • Ignition OFF.

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      C1280-9
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1458A-A4
      C1280-8
      GFD608930Courtesy of FORD MOTOR COMPANY
      		 C1458A-A4

    Is the resistance greater than 10K ohms? 

    Yes  GO to  X6
    No  REPLACE the harness, CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  7. X6 CHECK THE GENERATOR RESOLVER GR1 CIRCUIT FOR A SHORT

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 9, component side
      GFD608930Courtesy of FORD MOTOR COMPANY
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 all pins except pin 8, component side

    Is the resistance greater than 10K ohms? 

    Yes  GO to  X7
    No  INSTALL a new front electric drive assembly. REFER to: Front Electric Drive Assembly 
    CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  8. X7 CHECK THE GENERATOR RESOLVER GR2 CIRCUIT FOR A SHORT

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 8, component side
      GFD608930Courtesy of FORD MOTOR COMPANY
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 all pins except pin 9, component side

    Is the resistance greater than 10K ohms? 

    Yes  GO to  X8
    No  INSTALL a new front electric drive assembly. REFER to: Front Electric Drive Assembly 
    CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  9. X8 CHECK THE FRONT ELECTRIC GENERATOR RESOLVER RESISTANCES

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 4, component side
      GFD608930Courtesy of FORD MOTOR COMPANY
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 2, component side

    Is the resistance between 11.2 and 16.8 ohms? 

    Yes  GO to  X9
    No  INSTALL a new front electric drive assembly. REFER to: Front Electric Drive Assembly 
    CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  10. X9 CHECK THE FRONT ELECTRIC GENERATOR RESOLVER RESISTANCES

    • Ignition OFF.

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 5, component side
      GFD608930Courtesy of FORD MOTOR COMPANY
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 3, component side

    Is the resistance between 11.6 and 17.4 ohms? 

    Yes  GO to  X10
    No  INSTALL a new front electric drive assembly. REFER to: Front Electric Drive Assembly 
    CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  11. X10 CHECK THE FRONT ELECTRIC GENERATOR RESISTANCES

    • Measure and record:
      Positive Lead Measurement / Action Negative Lead
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 9, component side
      GFD608930Courtesy of FORD MOTOR COMPANY
      GFD609110Courtesy of FORD MOTOR COMPANY

      C1280 pin 8, component side

    Is the resistance between 7.6 and 11.4 ohms? 

    Yes  GO to  X11
    No  INSTALL a new front electric drive assembly. REFER to: Front Electric Drive Assembly 
    CLEAR the Secondary Inverter System Controller (S-ISC) DTCs. REPEAT the self-test.

  12. X11 TEST DRIVE VEHICLE

    • Reconnect all previously disconnected connectors.

    • CLEAR the Secondary Inverter System Controller (S-ISC) DTCs.

    • Test drive the vehicle, accelerate and decelerate quickly.

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

    Is DTC P0A4D present? 

    Yes  GO to  X12
    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.

  13. X12 CHECK FOR APPLICABLE SERVICE ARTICLES

    • CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA.

    Was a service article found? 

    Yes  DISCONTINUE this test and FOLLOW the service article instructions.
    No  GO to Pinpoint Test V 
    (In step V4 continue through to step V5 regardless of DTC presence.)
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