Ford 2003 Mustang Workshop Manual page 2363

PINPOINT TEST E: OUTPUT SHAFT SPEED (OSS) SENSORS
NOTE: Refer to the Output Shaft Speed (OSS) Sensor Harness Connector illustration preceding
these pinpoint tests.
E1 ELECTRONIC DIAGNOSTICS
Check to make sure the transmission harness
connector is fully seated, pins are fully engaged in
connector and in good condition before proceeding.
Connect the diagnostic tool.
Key in ON position.
Enter the following diagnostic mode on the diagnostic
tool: Diagnostic Data Link.
Enter the following diagnostic mode on the diagnostic
tool: PCM.
Select PID/Data Monitor and Record.
Select the PID OSS.
Does vehicle enter PID/Data Monitor and Record?
E2 DRIVE CYCLE TEST
While monitoring the OSS Speed PID, drive the
vehicle so that the transmission upshifts and
downshifts through all gears.
Does the OSS Speed PID increase and decrease
with engine and vehicle speed?
E3 CHECK RESISTANCE OF OSS SENSOR
Disconnect the vehicle harness connector from the
OSS sensor.
Measure the resistance between the OSS sensor pins.
Test Step Result / Action to Take
Yes
GO to E2 .
No
REPEAT procedure to ENTER
PID. If vehicle did not enter PID,
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual for diagnosis of
PCM.
Yes
CLEAR all DTCs. ROAD TEST to
verify if concern is still present. If
concern is still present, REFER to
Diagnosis By Symptom
section.
No
If the OSS Speed PID does not
increase and decrease with
engine and vehicle speed,
INSPECT for open or short in
vehicle harness, sensor, a PCM
concern, or internal hardware
concern.
If the sensor signal is erratic,
INSPECT for intermittent concern
in the internal/external harness,
sensor, or connector.
If the sensor signal is steady, GO
to E3 .
Yes
REFER to Diagnosis By
Symptom for concern diagnosis.
No
INSTALL a new OSS sensor.
in this