Pinpoint Test E: OSS Sensor

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to the TRANSMISSION VEHICLE HARNESS CONNECTOR illustration within the Transmission Connector Layouts procedure.

NOTE: Refer to the TRANSMISSION LEADFRAME CONNECTOR illustration within the Transmission Connector Layouts procedure.

NOTE: If the scan tool is unable to access the transmission PIDs, refer to the ENGINE CONTROLS - INTRODUCTION (EXCEPT DIESEL & HYBRID) (SECTION 0) .

NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws.

NOTE: Read and record all DTCs.

NOTE: If DTCs P0706, P0707, P0708, P0709, P1702 and/or P1921 are set, diagnose those DTCs first.

E1 DRIVE CYCLE TEST
- Connect the scan tool.
- Enter the following diagnostic mode on the scan tool: OSS PID: OSS_SRC.
- Monitor the OSS_SRC PID while road testing the vehicle. Drive the vehicle so the transmission upshifts and downshifts through all the gears.
- Does the OSS sensor rpm increase and decrease with engine rpm and vehicle speed?
- Yes : REFER to DIAGNOSIS BY SYMPTOM for further diagnosis.
- No : GO to E2.
E2 CHECK OSS SENSOR SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Transmission Vehicle Harness C1575.
- Disconnect: PCM C1381T.
- Disconnect: PCM C175T.
- Check to make sure the transmission vehicle harness C1575 and the PCM connectors are fully seated, terminals are fully engaged in the connector and are in good condition before proceeding.
- For vehicles equipped with a 3.7L engine, measure the resistance between the transmission vehicle harness C1575-15 circuit VET26 (BN/GN) and PCM C1381T-25.
  
  Fig 1: Measuring Resistance Between Transmission Vehicle Harness C1575-15 Circuit VET26 (BN/GN) And PCM C1381T-25
  Courtesy of FORD MOTOR CO.
- For vehicles equipped with a 5.0L (4V) engine, measure the resistance between the transmission vehicle harness C1575-15 circuit VET26 (BN/GN) and PCM C175T-14.
  
  Fig 2: Measuring Resistance Between Transmission Vehicle Harness C1575-15 Circuit VET26 (BN/GN) And PCM C175T-14
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to E3.
- No : REPAIR circuit VET26 (BN/GN) for an open. CLEAR the DTCs. TEST the system for normal operation.
E3 CHECK OSS SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- For vehicles equipped with a 3.7L engine, measure the resistance between the transmission vehicle harness PCM C1381T-25 circuit VET26 (BN/GN) and ground.
  
  Fig 3: Measuring Resistance Between Transmission Vehicle Harness PCM C1381T-25 Circuit VET26 (BN/GN) And Ground
  Courtesy of FORD MOTOR CO.
- For vehicles equipped with a 5.0L (4V) engine, measure the resistance between the transmission vehicle harness PCM C175T-14 circuit VET26 (BN/GN) and ground.
  
  Fig 4: Measuring Resistance Between Transmission Vehicle Harness PCM C175T-14 Circuit VET26 (BN/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 10, 000 ohms?
- Yes : GO to E4.
- No : REPAIR circuit VET26 (BN/GN) for a short to ground.
  CLEAR the DTCs. TEST the system for normal operation.
E4 CHECK OSS SENSOR SIGNAL CIRCUIT FOR A SHORT TO POWER
- Ignition ON.
- For vehicles equipped with a 3.7L engine, measure the voltage between the transmission vehicle harness PCM C1381T-25 circuit VET26 (BN/GN) and ground.
  
  Fig 5: Measuring Voltage Between Transmission Vehicle Harness PCM C1381T-25 Circuit VET26 (BN/GN) And Ground
  Courtesy of FORD MOTOR CO.
- For vehicles equipped with a 5.0L (4V) engine, measure the voltage between the transmission vehicle harness PCM C175T-14 circuit VET26 (BN/GN) and ground.
  
  Fig 6: Measuring Voltage Between Transmission Vehicle Harness PCM C175T-14 Circuit VET26 (BN/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR circuit VET26 (BN/GN) for a short to voltage.
  CLEAR the DTCs. TEST the system for normal operation.
- No : GO to E5.
E5 CHECK OSS SENSOR SIGNAL CIRCUIT FOR POWER
- Ignition OFF.
- Connect: PCM C1381T.
- Connect: PCM C175T.
- Ignition ON.
- Measure the voltage between the transmission vehicle harness C1575-15 circuit VET26 (BN/GN) and C1575-11 circuit RET24 (BN/BU).
  
  Fig 7: Measuring Voltage Between Transmission Vehicle Harness C1575-15 Circuit VET26 (BN/GN) And C1575-11 Circuit RET24 (BN/BU)
  Courtesy of FORD MOTOR CO.
- Is the voltage less than 4.8 volts?
- Yes : INSPECT and REPAIR circuit RET24 (BN/BU) for an open. If an open is not found, REPLACE the PCM, REFER to ELECTRONIC ENGINE CONTROLS . PROGRAM the PCM with the latest calibration level. PERFORM the SOLENOID BODY STRATEGY DATA DOWNLOAD procedure. REFER to SOLENOID BODY STRATEGY . TEST the system for normal operation.
- No : GO to E6.
E6 CHECK OSS SENSOR VPWR CIRCUIT FOR POWER
- Measure the voltage between the transmission vehicle harness C1575-12 circuit LE111 (VT/GN) and C1575-11 circuit RET24 (BN/BU).
  
  Fig 8: Measuring Voltage Between Transmission Vehicle Harness C1575-12 Circuit LE111 (VT/GN) And C1575-11 Circuit RET24 (BN/BU)
  Courtesy of FORD MOTOR CO.
- Is the voltage less than 9.5 volts?
- Yes : INSPECT and REPAIR circuit LE111 (VT/GN) for an open. If an open is not found, REPLACE the PCM, REFER to ELECTRONIC ENGINE CONTROLS . PROGRAM the PCM with the latest calibration level. PERFORM the SOLENOID BODY STRATEGY DATA DOWNLOAD procedure. REFER to SOLENOID BODY STRATEGY . TEST the system for normal operation.
- No : REPLACE the molded leadframe, REFER to SHIFT SOLENOIDS (SS) . CLEAR the DTCs. TEST the system for normal operation