Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
 
Vehicle » Powertrain Management » Computers and Control Systems » Testing and Inspection » Pinpoint Tests » TJ: Output Shaft Speed (OSS) Sensor - Pinpoint Test  
 
 
  TJ: Output Shaft Speed (OSS) Sensor - Pinpoint Test  
 

TJ: Output Shaft Speed (OSS) Sensor

TJ: Introduction See: TJ: Output Shaft Speed (OSS) Sensor - Introduction

TJ1 DTC P0720, P0721, P0722, P0723, AND P1900: VERIFY DRIVE CYCLE

  • Monitor the OSS PID.
  • Drive vehicle.
  • Through all gear ranges, shift up and down.

Does PID reading increase and decrease with engine and vehicle speed?
Yes

  • OSS performed as expected. GO to TJ2

.

No

  • For Hall Effect Type OSS:
  • KEY OFF. GO to TJ3

.

  • For VR Type OSS:
  • GO to TJ5

.

TJ2 VISUAL INSPECTION

  • Disconnect OSS sensor.
  • Inspect OSS harness for damage. Inspect OSS vehicle harness connector for damage and proper seating.
  • If possible, complete wiggle test.

Have any problems been found?
Yes

  • REPAIR fault.

No

for intermittent fault diagnosis.

TJ3 CHECK VPWR TO OSS SENSOR

  • Key on.
  • Disconnect OSS sensor.
  • Measure VPWR circuit voltage at OSS sensor harness connector.

Is voltage greater than 10.5 volts?
Yes

  • KEY OFF. GO to TJ4

.

No

  • KEY OFF. Repair open circuit.

TJ4 CHECK VPWR GND TO OSS SENSOR

  • Measure resistance of PWR GND circuit between OSS sensor harness connector and negative battery post.

Is resistance less than 5.0 ohms?
Yes

  • GO to TJ5

.

No

  • Repair open circuit.

TJ5 CHECK HARNESS FOR SHORT TO PWR

  • Key on.
  • Disconnect OSS sensor.
  • Measure voltage between the OSS signal circuit at the OSS sensor harness connector and ground.

Is voltage less than 1.0 volt?
Yes

  • KEY OFF. GO to TJ6

.

No

  • KEY OFF. REPAIR short circuit.

TJ6 CHECK HARNESS FOR OPEN

  • Disconnect PCM.
  • Measure resistance of the OSS signal circuit between the OSS sensor harness connector and the PCM harness connector.
  • Measure resistance of the OSS SIG RTN circuit between the OSS sensor harness connector and the PCM harness connector.

Is each resistance less than 5.0 ohms?
Yes

  • GO to TJ7

.

No

  • REPAIR short circuit.

TJ7 CHECK HARNESS FOR SHORT TO GROUND

  • Measure resistance between OSS signal and SIG RTN circuits at the OSS sensor harness connector.
  • Measure resistance between the OSS signal at the the OSS sensor harness connector and chassis ground.

Is each resistance greater than 10,000 ohms?
Yes

  • For VR Type OSS:
  • GO to TJ8

.

  • For Hall Effect Type OSS:
  • GO to TJ9

.

No

  • REPAIR short circuit.

TJ8 CHECK RESISTANCE OF OSS SENSOR

  • Measure resistance of the OSS sensor between the pins of the OSS sensor.

Is resistance between 450 and 750 ohms?
Yes

No

  • REPLACE OSS sensor.

TJ9 CHECK OSS SIGNAL OUTPUT TO PCM, HALL TYPE OSS

  • Disconnect PCM.
  • Raise vehicle to allow rotation of the front drive wheel.
  • Key on, transmission in neutral.
  • Measure voltage between OSS+ and PWR GND circuits at the PCM harness connector while slowly rotating the drive wheel.

Note: Opposite wheel must be held stationary.

  • The voltage should rise above 5.0 volts and fall below 1.0 volts in a regular cycle. Observe several cycles.

Does the OSS output voltage rise and fall as specified?
Yes

No

  • REPLACE OSS sensor. REFER to the diagnostic/repair information for manual transmissions.