Pinpoint Test D: OSS Sensor

WARNING: This page is about a different variant/trim than selected.

Refer to ELECTRONIC ENGINE CONTROLS - 2.3L Wiring Diagrams for schematic and connector information. Refer to ELECTRONIC ENGINE CONTROLS - 5.0L Wiring Diagrams 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 transmission output shaft changes.

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 signal is showing 0 speed, but the engine speed and load show that the vehicle is accelerating. P0720 will illuminate the MIL.
PCM P0721:00	Output Shaft Speed Sensor Circuit Range/Performance: No Sub Type Information	This DTC indicates the OSS sensor is erratic. The signal is changing by more than 400 RPM every 100 ms for greater than 25 seconds.
PCM P0722:00	Output Shaft Speed Sensor Circuit No Signal: No Sub Type Information	This DTC sets in conjunction with P0720. P0722 will not illuminate the MIL, but will set after a single drive cycle fault.

Possible Sources

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

Visual Inspection and Pre-checks

OSS sensor
OSS sensor connector

D1 DRIVE CYCLE TEST
- Using a diagnostic scan tool, access the PCM and monitor PID OSS_SRC.
- Road test the vehicle while monitoring PID OSS_SRC. Upshift and downshift through all gears.
Does the OSS sensor rpm steadily increase and decrease with vehicle speed?

Yes The concern is not present at this time.

No GO to D2

D2 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR
- Visually inspect the OSS sensor and connector for obvious signs of damage. Make sure the sensor is properly installed and the bolt is torqued to 10 Nm (89 in lb).
Were any conditions found during inspection?

Yes REPAIR as necessary.

No GO to D3

D3 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR VBPWR CIRCUIT FOR VOLTAGE

Ignition OFF.

Disconnect OSS sensor C1107 .

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
C1107-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 10.5 volts?

Yes

GO to D6

GO to D4

D4 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR VBPWR CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect PCM C1551E (for vehicles equipped with a 2.3L Ecoboost engine).

Disconnect PCM C175T (for vehicles equipped with a 5.0L Ti-VCT V8 engine).

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

For vehicles equipped with a 2.3L Ecoboost engine, measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-1	Courtesy of FORD MOTOR COMPANY	C1551E-70

For vehicles equipped with a 5.0L Ti-VCT V8 engine, measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-1	Courtesy of FORD MOTOR COMPANY	C175T-50

Is the resistance less than 3 ohms?

Yes

GO to D5

No	REPAIR the open circuit.

D5 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR VBPWR CIRCUIT FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to D8

No	REPAIR the short to ground.

D6 CHECK THE SENSOR SIGNAL AND SIGNAL RETURN CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect PCM C1551E (for vehicles equipped with a 2.3L Ecoboost engine).

Disconnect PCM C175T (for vehicles equipped with a 5.0L Ti-VCT V8 engine).

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

For vehicles equipped with a 2.3L Ecoboost engine, measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-2	Courtesy of FORD MOTOR COMPANY	C1551E-68
C1107-3	Courtesy of FORD MOTOR COMPANY	C1551E-62

For vehicles equipped with a 5.0L Ti-VCT V8 engine, measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-2	Courtesy of FORD MOTOR COMPANY	C175T-51
C1107-3	Courtesy of FORD MOTOR COMPANY	C175T-7

Are the resistances less than 3 ohms?

Yes

GO to D7

No	REPAIR the open circuit.

D7 CHECK THE SENSOR SIGNAL AND SIGNAL RETURN CIRCUITS FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1107-2	Courtesy of FORD MOTOR COMPANY	Ground
C1107-3	Courtesy of FORD MOTOR COMPANY	Ground

Are the resistances greater than 10, 000 ohms?

Yes	INSTALL a new OSS sensor. REFER to: Selector Shaft - 5.0L Ti-VCT V8 (308kW/418PS) .

No	REPAIR the short to ground.

D8 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the PCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the PCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new PCM. Refer to the appropriate Removal and Installation procedure in the appropriate Electronic Engine Controls article.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.