Test G: Output Shaft Speed Sensor (Sable & TAURUS)

Electronic Diagnostics

Ensure OSS sensor harness and component connector terminals are in good condition and seated properly. If connector and terminals are not okay, repair as necessary. If connector is okay, go to next step.

Check Continuity Of OSS Sensor Harness Circuit

Ensure ignition switch is turned to OFF position. Disconnect PCM 104-pin connector, and inspect it for damaged terminals, corrosion and loose wires. Repair as necessary. Install breakout box, leaving PCM disconnected. Disconnect OSS sensor harness connector. Measure and record resistance between breakout box test pin No. 84 and OSS sensor harness connector positive terminal (Dark Blue/Yellow wire). Measure and record resistance between breakout box test pin No. 91 and OSS sensor harness connector SIG RTN terminal (Gray/Red wire). If resistance readings are less than 5 ohms, go to next step. If any resistance readings are 5 ohms or more, repair open circuits. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING.

Check OSS Sensor Circuit For Short To Power & Ground

Measure and record resistance between specified breakout box test pins. See OSS SENSOR HARNESS SHORT CIRCUIT TEST table. If all resistance readings are more than 10 k/ohms, go to next step. If any resistance reading is 10 k/ohms or less, repair short circuit. Connect all components. Disconnect breakout box. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING.

OSS SENSOR HARNESS SHORT CIRCUIT TEST ⁽¹⁾

Breakout Box Test Pin No.

Breakout Box VPWR & Ground Test Pin No.

Sable & Taurus

71 & 91

71, 84 & 91

24, 25, 51, 76, 77, 103 & Chassis Ground

⁽¹⁾	Measure between specified breakout box test pins.

OSS Sensor Functional Test

Reconnect PCM connector. Ensure TSS sensor harness connector is disconnected. Connect transmission tester to OSS sensor connector. Connect voltmeter leads to transmission tester TSS/OSS sensor jacks. Set voltmeter to 20-volt AC scale. Perform TRANSAXLE DRIVE CYCLE TEST under DIAGNOSIS & TESTING. If voltage does not increase when vehicle speed increases, go to next step. If voltage increases when vehicle speed increases, replace PCM. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING.

Check Resistance Of OSS Sensor

Measure resistance between both TSS/OSS sensor jacks on transmission tester. If resistance reading is 235-735 ohms, go to next step. If resistance reading is not 235-735 ohms, replace OSS sensor. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING. Perform TRANSAXLE DRIVE CYCLE TEST under DIAGNOSIS & TESTING.

Check OSS Sensor For Short To Ground

Check for continuity between BAT (-) jack and each TSS/OSS sensor jacks on transmission tester. If continuity does not exist, go to next step. If continuity exists, replace OSS sensor. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING. Perform TRANSAXLE DRIVE CYCLE TEST under DIAGNOSIS & TESTING.

Check OSS Sensor Magnetism

Remove OSS sensor from transaxle. See FORD AX4N OVERHAUL article. Determine if OSS sensor is magnetically attracted to a ferrous metal surface. If OSS sensor sticks to ferrous metal surface, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Repeat QUICK TEST under DIAGNOSIS & TESTING. Perform TRANSAXLE DRIVE CYCLE TEST under DIAGNOSIS & TESTING. If OSS sensor does not stick to ferrous metal surface, replace OSS sensor. Connect all components. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES . Repeat QUICK TEST . Perform TRANSAXLE DRIVE CYCLE TEST .