Pinpoint Test E: Output Shaft Speed (OSS) Sensors
WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. 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 WARNING: If equipped with fire suppression system, depower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article.
- 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. If equipped with a fire suppression system, go to E6.
- 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 . If equipped with a fire suppression system, go to E6.
- 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?
- 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?
- 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 in this article for concern diagnosis. If equipped with a fire suppression system, go to E6.
- NO : INSTALL a new OSS sensor. If equipped with a fire suppression system, go to E6.
- E6 REPOWER THE FIRE SUPPRESSION SYSTEM WARNING: If equipped with fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article.
- Verify that the fire suppression system is repowered. Refer to FIRE SUPPRESSION SYSTEM article.
- Is the fire suppression system repowered?
- YES : Fire suppression system repowering is complete.
- NO : REFER to FIRE SUPPRESSION SYSTEM article for fire suppression system depowering and repowering procedure.