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Pinpoint Test C: OSS Sensor

NOTE: Refer to the transaxle connector illustrations and solenoid body leadframe internal wiring diagram in Transaxle Connector Layouts  in this service information.
NOTE: Output Shaft Speed (OSS) codes may be a result of a bad common power or ground shared between the Transmission Range (TR) sensor, OSS sensor and Turbine Shaft Speed (TSS) sensor.
  1. C1 ELECTRONIC DIAGNOSTICS 
    • Check to make sure the transaxle vehicle harness C1520A is fully seated, terminals are engaged in connector and in good condition before proceeding.
    • Have the items above been checked? 
    1. Yes  : GO to C2.
    2. No  : CARRY OUT the checks. CLEAR the codes. RERUN the On-Board Diagnostic (OBD) tests.
  2. C2 ELECTRONIC DIAGNOSTICS 
    • Connect the scan tool.
    • Monitor the OSS sensor PIDs while test driving the vehicle.
    • Is the OSS sensor signal present and consistent? 
    1. Yes  : The condition that set the DTC is intermittent and is not currently present. CLEAR the DTCs. RERUN the OBD tests.
    2. No  : GO to C3.
  3. C3 CHECK THE VEHICLE HARNESS FOR AN OPEN CIRCUIT 
    • Disconnect: Transaxle Vehicle Harness C1520A.
    • Disconnect: PCM Transaxle Harness C175T.
    • Use a mirror to inspect both ends of the connectors for damage or pushed-out terminals, corrosion, loose wires and missing or damaged seals.
    • Measure the resistance for the OSS sensor circuit, between the transaxle vehicle harness C1520A and the PCM transaxle harness C175T, harness using the following chart.
      Output Shaft Speed Sensor Circuit Transaxle Vehicle Harness PCM
      Output Shaft Speed (OSS) sensor power supply LE111 (VT/GN) C1520A-18 C175T-1
      OSS sensor ground RET24 (BN/BU) C1520A-20 C175T-36
      OSS sensor signal VET26 (BN/GN) C1520A-19 C175T-25
    • Is the resistance less than 5 ohms? 
    1. Yes  : GO to C4.
    2. No  : REPAIR the circuit(s) for an open. CONNECT all components. TEST the system for normal operation.
  4. C4 CHECK THE VEHICLE HARNESS FOR A SHORT TO GROUND 
    • Disconnect: Transaxle Vehicle Harness C1520B.
    • Measure the resistance for the OSS sensor circuit between the transaxle vehicle harness C1520A and ground using the following chart.
      Output Shaft Speed Sensor Circuit Transaxle Vehicle Harness Ground
      Transmission Range (TR)/ OSS sensor power supply LE111 (VT/GN) C1520A-18 Ground
      TR/OSS sensor ground RET24 (BN/BU) C1520A-20 Ground
      OSS sensor signal VET26 (BN/GN) C1520A-19 Ground
    • Is the resistance greater than 10,000 ohms? 
    1. Yes  : GO to C5.
    2. No  : REPAIR the circuit(s) for a short to ground. CONNECT all components. TEST the system for normal operation.
  5. C5 CHECK THE VEHICLE HARNESS FOR A SHORT TO VPWR 
    • Check for voltage between the OSS sensor circuits and the transaxle vehicle harness C1520A using the following chart.
      Output Shaft Speed Sensor Circuit Transaxle Vehicle Harness Ground
      Transmission Range (TR)/ OSS sensor power supply LE111 (VT/GN) C1520A-18 Ground
      TR/OSS sensor ground RET24 (BN/BU) C1520A-20 Ground
      OSS sensor signal VET26 (BN/GN) C1520A-19 Ground
    • Is any voltage present? 
    1. Yes  : REPAIR the circuit(s) for a short to voltage. CONNECT all components. TEST the system for normal operation.
    2. No  : GO to C6.
  6. C6 CHECK THE SOLENOID BODY FOR AN INTERNAL OPEN CIRCUIT 
    • Remove the main control cover. Refer to MAIN CONTROL COVER in this service information.
    • Disconnect: TR Sensor.
    • Disconnect: OSS Sensor.
    • Use a mirror to inspect both ends of the connectors for damage or pushed-out terminals, corrosion, loose wires and missing or damaged seals.
    • Measure the resistance of the solenoid body internal sensor power circuit between the main solenoid body leadframe connector pin 18, leadframe side and the OSS sensor connector pin 4, leadframe side.
      Fig 1: Measuring Resistance Between Main Solenoid Body Leadframe Connector Pin 18 And OSS Sensor Connector Pin 4
      G07782647Courtesy of FORD MOTOR CO.
    • Measure the resistance of the solenoid body internal sensor signal circuit between the main solenoid body leadframe connector pin 19, leadframe side and the OSS sensor connector pin 3, leadframe side.
      Fig 2: Measuring Resistance Between Main Solenoid Body Leadframe Connector Pin 19 And OSS Sensor Connector Pin 3
      G07782648Courtesy of FORD MOTOR CO.
    • Measure the resistance of the solenoid body internal sensor ground circuit between the main solenoid body leadframe connector pin 20, leadframe side and the OSS sensor connector pin 1, leadframe side.
      Fig 3: Measuring Resistance Between Main Solenoid Body Leadframe Connector Pin 20 And OSS Sensor Connector Pin 1
      G07782649Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    1. Yes  : GO to C7.
    2. No  : INSTALL a new solenoid body leadframe. REFER to SOLENOID BODY LEADFRAME in this service information. CONNECT all components. TEST the system for normal operation.
  7. C7 CHECK FOR VOLTAGE AND GROUND AT THE OSS SENSOR CONNECTOR 
    • Connect: PCM C175T.
    • Connect: Transaxle Vehicle Harness C1520A.
    • Ignition ON.
    • Measure the voltage on the solenoid body leadframe between OSS sensor connector pins 1 and 4.
      Fig 4: Measuring Voltage Solenoid Body Leadframe Between OSS Sensor Connector Pins 1 And 4
      G07782650Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    1. Yes  : INSTALL a new speed sensor. REFER to OUTPUT SHAFT SPEED (OSS) SENSOR in this service information. TEST the system for normal operation. If the condition is still present, INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - 2.5L FUSION & MILAN (EXCEPT HYBRID)--> article orELECTRONIC ENGINE CONTROLS - 3.0L (4V) FUSION & MILAN--> article.
    2. No  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - 2.5L FUSION & MILAN (EXCEPT HYBRID)--> article orELECTRONIC ENGINE CONTROLS - 3.0L (4V) FUSION & MILAN--> article. CONNECT all components. TEST the system for normal operation.
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