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Home >> Ford >> 2020 >> Expedition SSV, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 400 (Abs Guided Routine) >> Pinpoint Tests >> Pinpoint Tests OB: The Selectable Drive Mode Feature Is Inoperative >> Possible Causes
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Possible Causes

WARNING: This page is about a different car, the 2019 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
  1. OB1: CHECK FOR OTHER ABS MODULE DTCS 
    • Ignition ON, engine OFF.

    Carry out the ABS self-test.

    • Are any battery voltage or lost communication DTCs present in the ABS module? 
      Yes No
      DIAGNOSE all ABS module battery voltage and lost communication DTCs before diagnosing the selectable drive mode switch. GO to the ABS module DTC Chart. Go to  OB2.
  2. OB2: DETERMINE SELECTABLE DRIVE MODE CAPABILITY 
    • Press the Read Vehicle Information button to view the results of the modules communicating on the network.
    • Retrieve the continuous memory DTCs.
    • Is the vehicle equipped with an ATCM? 
      Yes No
      Go to  OB13. Go to  OB5.
  3. OB3: VERIFY THE TCM COMMUNICATES ON THE NETWORK 
    • Press the Read Vehicle Information button to view the results of the modules communicating on the network.
    • Retrieve the continuous memory DTCs.
    • Does the TCM pass the Network Test? 
      Yes No
      Go to  OB4. REFER to the Module Communications Network article to diagnose the TCM does not respond to the diagnostic scan tool.
  4. OB4: CHECK FOR TCM DTCS 

    Carry out the TCM self-test.

    • Are any DTCs present in the TCM? 
      Yes No
      DIAGNOSE all TCM DTCs before diagnosing the selectable drive mode switch. REFER to the appropriate procedure in Automatic Transmission article. Go to  OB7.
  5. OB5: VERIFY THE PCM COMMUNICATES ON THE NETWORK 
    • Press the Read Vehicle Information button to view the results of the modules communicating on the network.
    • Retrieve the continuous memory DTCs.
    • Does the PCM pass the Network Test? 
      Yes No
      Go to  OB6. REFER to the Module Communications Network article to diagnose the PCM does not respond to the diagnostic scan tool.
  6. OB6: CHECK FOR PCM DTCS 

    Carry out the PCM KOEO self-test.

    • Are any DTCs present in the PCM? 
      Yes No
      DIAGNOSE all PCM DTCs before diagnosing the selectable drive mode switch. REFER to the appropriate procedure in Electronic Engine Controls article. Go to  OB10.
  7. OB7: CHECK FOR VOLTAGE TO THE DRIVE MODE SWITCH 
    • Ignition OFF.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) (-)
      Column Shifter Connector, Harness Side  
      SDM-V Ground
    • Measure the voltage between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side  
      SDM-V Ground
    • Measure the voltage between:
      (+) (-)
      OD Connector, Harness Side  
      IGN START/RUN Ground
    • Is the voltage above 11 volts? 
      Yes No
      Go to  OB8. REPAIR the circuit.
  8. OB8: CHECK THE SELECTABLE DRIVE MODE CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
      (+) (-)
      Column Shifter Connector, Harness Side TCM Connector, Harness Side
      SDM SDM
    • Measure the resistance between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side PCM B (C175B) Connector, Harness Side
      SDM SDM
    • Measure the resistance between:
      (+) (-)
      OD Connector, Harness Side TCM Connector, Harness Side
      SDM SDM
    • Is the resistance less than 3 ohms? 
      Yes No
      Go to  OB9. REPAIR the circuit.
  9. OB9: CHECK THE SELECTABLE DRIVE MODE CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) (-)
      Column Shifter Connector, Harness Side  
      SDM Ground
    • Measure the resistance between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side  
      SDM Ground
    • Measure the resistance between:
      (+) (-)
      OD Connector, Harness Side  
      SDM Ground
    • Is the resistance greater than 10, 000 ohms? 
      Yes No
      INSTALL a new column shifter assembly (the switch is part of the shifter assembly) or transmission range selector. REFER to the appropriate procedure in the Automatic Transmission External Controls article. REPAIR the circuit.
  10. OB10: CHECK FOR VOLTAGE TO THE TOW-HAUL SWITCH 
    • Ignition OFF.
    • Column Shifter connector disconnected. (if equipped)
    • Floor Shifter Assembly connector disconnected. (if equipped)
    • PCM_B connector disconnected. (C175B)
    • Ignition ON, engine OFF.
      NOTE: Verify BCM fuse 35 (5A) is OK. If not OK, refer to the OEM Electrical Wiring Diagram Introduction article to identify the cause of the circuit short.
    • Measure the voltage between:
      (+) (-)
      Column Shifter Connector, Harness Side  
      SDM-V Ground
    • Measure the voltage between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side  
      SDM-V Ground
    • Is the voltage above 11 volts? 
      Yes No
      Go to  OB11. REPAIR the circuit.
  11. OB11: CHECK THE SELECTABLE DRIVE MODE CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
      (+) (-)
      Column Shifter Connector, Harness Side PCM_B (C175B) Connector, Harness Side
      SDM SDM
    • Measure the resistance between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side PCM B (C175B) Connector, Harness Side
      SDM SDM
    • Is the resistance less than 3 ohms? 
      Yes No
      Go to  OB12. REPAIR the circuit.
  12. OB12: CHECK THE SELECTABLE DRIVE MODE CIRCUIT FOR AN OPEN 
    • Measure the resistance between:
      (+) (-)
      Column Shifter Connector, Harness Side  
      SDM Ground
    • Measure the resistance between:
      (+) (-)
      Floor Shifter Assembly Connector, Harness Side  
      SDM Ground
    • Is the resistance greater than 10, 000 ohms? 
      Yes No
      INSTALL a new floor shifter or column shifter assembly, the tow-haul switch is part of the shifter assembly. REFER to the appropriate procedure in the Automatic Transmission External Controls article. REPAIR the circuit.
  13. OB13: CHECK FOR ATCM DTCS 
    • Review the results from the previous network test.
    • Are any DTCs present in the ATCM? 
      Yes No
      DIAGNOSE all ATCM DTCs before diagnosing the selectable drive mode switch. REFER to the Four-Wheel Drive Systems article. Go to  OB14.
  14. OB14: CHECK THE VOLTAGE TO THE ATCM 
    • Ignition OFF.
    • ATCM connector disconnected. (C3685)
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) (-)
      ATCM (C3685) Connector, Harness Side  
      B+ - CBB23 (BROWN/YELLOW) - Pin 1 Ground
    • Is the voltage greater than 11 volts? 
      Yes No
      Go to  OB15. REPAIR the circuit.
  15. OB15: CHECK THE ATCM GROUND CIRCUIT FOR AN OPEN 
    • Measure the resistance between:
      (+) (-)
      ATCM (C3685) Connector, Harness Side  
      GND - GD343 (BLACK/VIOLET) - Pin 7 Ground
    • Is the resistance less than 3 ohms? 
      Yes No
      INSTALL a new ATCM.
      REFER to the Four-Wheel Drive Systems article.      		 REPAIR the circuit.
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