Pinpoint Test E: Output Shaft Speed (OSS) Sensors
WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Refer to the Output Shaft Speed (OSS) Sensor Harness Connector illustration in Transmission Connector Layouts .
- E1 ELECTRONIC DIAGNOSTICS
- Vehicle in PARK.
- Key in OFF position.
- Check to make sure the transmission harness connector is fully seated, pins are fully engaged in connector and in good condition before proceeding.
- Connect the diagnostic tool.
- Key in ON position.
- Access the transmission PIDs.
- Is the scan tool able to access the transmission PIDs?
- YES : Go to E2.
- NO : REPEAT procedure to access the transmission PIDs. If the scan tool did not access the transmission PIDs, REFER to the Introduction - Gasoline Engines article for diagnosis of PCM.
- E2 DRIVE CYCLE TEST
- While monitoring the OSS_SRC PID, drive the vehicle so that the transmission upshifts and downshifts through all gears.
- Does the OSS_SRC PID increase and decrease with vehicle speed?
- YES : CLEAR all DTCs. ROAD TEST to verify if concern is still present. If concern is still present, REFER to Diagnosis By Symptom .
- NO
: If the OSS PID does not increase and decrease with vehicle speed, INSPECT for open or short in vehicle harness, sensor, a PCM concern or internal hardware concern. Go to E3.
If the sensor signal is erratic, INSPECT for intermittent concern in the internal/external harness, sensor or connector.
If the sensor signal is consistent/unchanging output, go to E3 .
- E3 CHECK THE PCM HARNESS FOR OPENS
- Disconnect: PCM C175T
- Disconnect: Output Shaft Speed (OSS) Sensor C1107
- Measure the resistance between PCM C175T-3, circuit 136 (DB/YE), harness side and OSS C1107-2, circuit 136 (DB/YE), harness side.
- Measure the resistance between PCM C175T-41, circuit 359 (GY/RD), harness side and OSS C1107-1, circuit 359 (GY/RD), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to E4.
- NO : REPAIR the circuit. TEST the system for normal operation.
- E4 CHECK THE PCM HARNESS FOR SHORT TO GROUND
- Measure the resistance between PCM C175T-3, circuit 136 (DB/YE), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to E5.
- NO : REPAIR circuit 136 (DB/YE). TEST the system for normal operation.
- E5 CHECK RESISTANCE OF THE OSS SENSOR
- Disconnect the vehicle harness connector from the OSS sensor.
- Remove the OSS sensor from the transmission.
- Measure the resistance between the OSS sensor pins, component side.
- Is the resistance between 400-500 ohms at 25°C (77°F)?
- YES : REFER to Diagnosis By Symptom for concern diagnosis.
- NO : INSTALL a new OSS sensor.