Pinpoint Test L : DTCS P0720, P0721, P0722
WARNING: This page is about a different car, the 2018 Ford EcoSport. However, it is still accessible from the selected car via links, so may be relevant.
- Refer to TRANSMISSION CONTROLS
for schematic and connector information.
Normal Operation and Fault Conditions
The OSS sensor is a Hall-effect sensor that sends a signal to the PCM that indicates transmission output shaft speed. The OSS sensor is used for TCC control and shift scheduling.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P0720:00 Output Shaft Speed Sensor Circuit: No Sub Type Information No input from the OSS sensor. PCM P0721:00 Output Shaft Speed Sensor Circuit Range/Performance: No Sub Type Information Unrealistic change in the OSS sensor signal, erratic or intermittently no input. PCM P0722:00 Output Shaft Speed Sensor Circuit No Signal: No Sub Type Information No input from the OSS sensor. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- OSS sensor
- PCM
- L1 RETRIEVE AND RECORD ALL DTCS
- Using the diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs).
Are diagnostic trouble codes (DTCs) P0720, P0721, P0722 and/or P0715, present?
Yes GO to L2 No REFER to: Diagnosis By Symptom . - L2 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR VEHICLE POWER CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect Transmission Harness C1520.
- 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 C1520-18 Ground
Is the voltage greater than 11 volts?
Yes GO to L3 No REPAIR the open circuit, if an open circuit is not found, Refer to PCM GUIDED ROUTINE TESTING CARRY OUT the Transmission Strategy Download, REFER to: Transmission Strategy Download - L3 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR GROUND CIRCUIT
- Ignition ON.
Is the voltage greater than 11 volts?
Yes GO to L4 No REPAIR the circuit. - L4 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR SIGNAL CIRCUIT FOR AN OPEN
- Ignition ON.
Is the voltage greater than 4.5 volts?
Yes GO to L5 No INSPECT and REPAIR the circuit. If an open circuit is not found, Refer to PCM GUIDED ROUTINE TESTING CARRY OUT the Transmission Strategy Download, REFER to: Transmission Strategy Download - L5 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR CIRCUITS IN THE TRANSMISSION INTERNAL WIRING HARNESS FRAME FOR AN OPEN
- Remove the main control cover. REFER to: Main Control Cover - 1.0L EcoBoost (92kW/125PS) .
- Disconnect OSS Sensor.
- Inspect the connector for damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals.
- Measure:
Positive Lead Measurement / Action Negative Lead Component side, C1520-19 OSS sensor internal harness, pin 3 Component side, C1520-18 OSS sensor internal harness, pin 4 Component side, C1520-20 OSS sensor internal harness, pin 1
Is the resistance less than 3 ohms?
Yes GO to L6 No INSTALL a new transmission internal wiring harness frame. REFER to: Transmission Internal Wiring Harness Frame . - L6 CHECK THE OSS (OUTPUT SHAFT SPEED) SENSOR CIRCUITS IN THE TRANSMISSION INTERNAL WIRING HARNESS FRAME FOR A SHORT TO GROUND
- Measure:
Positive Lead Measurement / Action Negative Lead Component side, C1520-19 Ground Component side, C1520-18 Ground Component side, C1520-20 Ground
Is the resistance 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 frame. REFER to: Transmission Internal Wiring Harness Frame . - Measure: