Pinpoint Test E : OSS (Output Shaft Speed) Sensor

WARNING: This page is about a different car, the 2019 Ford F-350 Super Duty and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

Transmission Controls - 6R100 for schematic and connector information.

Normal Operation and Fault Conditions

The OSS sensor is a Hall-effect type sensor that provides a signal to the PCM that changes in frequency as the rotating speed of the output shaft ring gear varies. The PCM also compares the OSS sensor signal with the TSS sensor signal to determine the gear ratio provided by the rear planetary gearset. The PCM uses the OSS sensor signal as an input for its strategies for shifts and TCC operation. The PCM also uses the OSS sensor signal for transmission fault detection and diagnostics.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM P0720:00	Output Shaft Speed Sensor Circuit: No Sub Type Information	This DTC indicates the OSS sensor reads 0 speed when vehicle conditions (mainly the TSS sensor) indicate the output shaft should be rotating. This could be caused by an open circuit, a short to ground or a short to power in the OSS sensor circuit, or by a failed sensor.
PCM P0721:00	Output Shaft Speed Sensor Circuit Range/Performance: No Sub Type Information	This DTC indicates an unrealistic change or an intermittent/noisy signal from the OSS sensor. This could be caused by an intermittent open circuit, short to ground or short to power in the OSS sensor circuit, or by a failed sensor.
PCM P0722:00	Output Shaft Speed Sensor Circuit No Signal: No Sub Type Information	This DTC illuminates the wrench light in conjunction with P0720. Resolve the more specific DTC first.

Possible Sources

Connectors damaged or pushed-out terminals, corrosion, loose wires or ground and missing or damaged seals
OSS sensor
PCM

E1 DRIVE CYCLE TEST

NOTE: Read and record all DTCs.

NOTE: If DTCs P0705, P0706, P0707, P0708, P0709, P1702, P1705 and/or P1921 are set, diagnose those DTCs first.
- Using the diagnostic scan tool, monitor the OSS sensor PID OSS_SRC while road testing the vehicle. Drive the vehicle so the transmission upshifts and downshifts through all the gears.
Does the OSS sensor rpm steadily increase and decrease with vehicle speed?

Yes The OSS sensor is operating correctly at this time.

No GO to E2

E2 CHECK FOR TSS DTCS
- Enter the following diagnostic mode: PCM Self-Test.
Are TSS diagnostic trouble codes (DTCs) P0715, P0716, or P0717 present?

Yes GO to Pinpoint Test D

No GO to E3

E3 CHECK THE OSS SENSOR SIGNAL CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: PCM C175E.

Disconnect Transmission Vehicle Harness C1575.

Inspect the connectors for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.

Measure:

Positive Lead	Measurement / Action	Negative Lead
Refer to C1575-15	Courtesy of FORD MOTOR COMPANY	Refer to C175E-26

Is the resistance less than 3 ohms?

Yes

GO to E4

No	REPAIR transmission vehicle harness OSS sensor signal circuit for an open.

E4 CHECK THE OSS SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
Refer to C1575-15	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes	INSTALL a new molded leadframe, REFER to: Shift Solenoids (SS) . CLEAR the DTCs.

No	REPAIR transmission vehicle harness OSS sensor signal circuit for a short to ground.