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Test TC-166A - Low Output Speed Sensor Rpm Above 15 Mph

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION DIRECTORY. For component location see wiring diagram in the WIRING DIAGRAMS article.
WARNING: Keep hands and feet clear of rotating wheels.
  1. Using scan tool, read DTCs. If P/N SWITCH STUCK IN PARK OR IN GEAR DTC is present, repair this DTC before proceeding. If DTC is not present, go to next step.
  2. Raise and support vehicle so drive wheels are free to rotate. Start engine. Using scan tool, read Output Speed Sensor (OSS) signal. Place transmission in any forward gear. If scan tool displays 60 MPH or less, go to step 7). If scan tool displays more than 60 MPH, go to next step.
  3. While monitoring OSS signal, wiggle connectors and wiring harness from OSS to Powertrain Control Module (PCM). If reading drops toward zero MPH while wiggling connectors and harness, repair connector or harness that caused drop and perform TEST VER-2A. If reading does not change, go to next step.
  4. Using scan tool, erase DTCs. Road test vehicle. Using scan tool, read DTCs. If LOW OUTPUT SPEED SENSOR DTC does not return, go to step 6). If DTC returns, go to next step.
  5. Replace OSS. Using scan tool, erase DTCs. Road test vehicle. Using scan tool, read DTCs. If LOW OUTPUT SPEED SENSOR DTC does not return, go to next step. If DTC returns, replace PCM and perform TEST VER-1A.
  6. Condition required to set DTC is not present at this time. LOW OUTPUT SPEED SENSOR RPM DTC sets if no OSS signal (23 pulses per output shaft revolution) is received at PCM. Possible causes are: defective OSS, defective connections, no pulses, defective wiring, or defective PCM. Test is complete.
  7. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-1A. If connectors and terminals are okay, go to next step.
  8. Using an external ohmmeter, check resistance between ground and PCM White connector, OSS signal circuit (Light Green/White wire). If resistance is less than 5 ohms, repair OSS signal circuit for short to ground and perform TEST VER-1A. If resistance is 5 ohms or more, go to next step.
  9. Check resistance between ground and PCM White connector, ground circuit (Dark Green/Black wire). If resistance is 5 ohms or less, repair ground circuit for short to ground and perform TEST VER-1A. If resistance is more than 5 ohms, go to next step.
  10. Check resistance between PCM White connector, OSS signal circuit (Light Green/White wire) and ground circuit (Dark Green/Black wire). If resistance is 300-1200 ohms, replace PCM and perform TEST VER-1A. If resistance is not as specified, go to next step.
  11. Disconnect OSS connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-1A. If connector and terminals are okay, go to next step.
  12. Check resistance across OSS connector. If resistance is not 300-1200 ohms, replace OSS and perform TEST VER-1A. If resistance is as specified, go to next step.
  13. Check resistance of OSS signal circuit (Light Green/White wire) between PCM white connector and OSS connector. If resistance is more than 5 ohms, repair open OSS signal circuit and perform TEST VER-1A. If resistance is 5 ohms or less, repair open OSS ground circuit and perform TEST VER-2A.
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