Pinpoint Test E : OSS (Output Shaft Speed) Sensor

WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 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 - TorqShift 6 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 s are set.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM P0720:00	Output Shaft Speed Sensor Circuit: No Sub Type Information	This DTC sets if the PCM detects an open, a short to ground or a short to power condition in the OSS sensor circuitry.
PCM P0721:00	Output Shaft Speed Sensor Circuit Range/Performance: No Sub Type Information	This DTC sets if the PCM detects an intermittent open, an intermittent short to ground or an intermittent short to power condition in the TSS sensor circuitry.
PCM P0722:00	Output Shaft Speed Sensor Circuit No Signal: No Sub Type Information	This DTC sets relationally if the DTC P0720 is set, RESOLVE this DTCs first.

Possible Sources

Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
OSS sensor
Transmission internal wiring harness
PCM fault

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 increase and decrease with vehicle speed?

Yes The concern is not present at this time.

No GO to E2

E2 CHECK THE OSS SENSOR SIGNAL CIRCUIT FOR VOLTAGE

Ignition OFF.

Disconnect Transmission Vehicle Harness C1623.

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

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
Refer to C1623-17	Courtesy of FORD MOTOR COMPANY	Ground

Is voltage present?

Yes

GO to E5

GO to E3

E3 CHECK THE OSS SENSOR SIGNAL CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect PCM C175E.

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

Measure:

Positive Lead	Measurement / Action	Negative Lead
Refer to C1623-17	Courtesy of FORD MOTOR COMPANY	Refer to C175E-26

Is the resistance less than 3 ohms?

Yes

GO to E4

No	REPAIR the circuit.

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

Measure:

Positive Lead	Measurement / Action	Negative Lead
Refer to C1623-17	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes	Refer to PCM GUIDED ROUTINE TESTING After installing a new PCM, CARRY OUT the transmission strategy download. REFER to: Transmission Strategy Download .

No	REPAIR the circuit.

E5 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS FOR AN OPEN

Remove the transmission fluid pan and filter. REFER to: Transmission Fluid Pan, Gasket and Filter .

Disconnect the OSS sensor connector.

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

Measure the resistance of the OSS sensor circuits between the transmission bulkhead connector and the OSS sensor connector:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 1	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY Transmission component side, Pin 10
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 3	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY Transmission component side, Pin 17
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 4	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY Transmission component side, Pin 12

Are the resistances less than 3 ohms?

Yes

GO to E6

No	INSTALL a new transmission internal wiring harness. REFER to: Transmission Internal Wiring Harness .

E6 CHECK THE TRANSMISSION INTERNAL WIRING HARNESS FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 1	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 3	Courtesy of FORD MOTOR COMPANY	Ground
Courtesy of FORD MOTOR COMPANY OSS sensor connector, harness side, Pin 4	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	INSTALL a new OSS sensor. REFER to: Output Shaft Speed (OSS) Sensor .

No	INSTALL a new transmission internal wiring harness. REFER to: Transmission Internal Wiring Harness .