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

NOTE: For connector terminal identification, refer to CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article in this section.
  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.
    WARNING: Keep hands and feet clear of rotating wheels.
  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 zero MPH, go to step 5). If scan tool displays more than zero MPH, go to next step.
  3. 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 Powertrain Control Module (PCM). Possible causes are: defective OSS, defective connections, no pulses, defective wiring, or defective PCM. Go to next step.
  4. Inspect all related wiring and connectors. Repair wiring and connectors as necessary and perform TEST VER-1A . If wiring and connectors are okay, see INACTIVE DTC CONDITION . VSS test okay at this time. Perform TEST VER-1A.
  5. 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.
  6. Using scan tool in ohmmeter mode, check resistance of PCM White connector, OSS signal circuit (Light Green/White wire). If resistance is 5 ohms or more, go to step 9). If resistance is less than 5 ohms, go to next step.
  7. 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.
  8. Check resistance of PCM White connector, OSS signal circuit (Light Green/White wire). If resistance is 5 ohms or more, replace OSS and perform TEST VER-1A . If resistance is less than 5 ohms, repair short to ground in OSS signal circuit and perform TEST VER-1A.
  9. Using an external ohmmeter, check resistance between PCM White connector, OSS signal circuit (Light Green/White wire) and OSS ground circuit (Dark Blue/Black wire). If resistance is 300-1200 ohms, replace PCM and perform TEST VER-1A . If resistance is not 300-1200 ohms, go to next step.
  10. 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.
  11. Check resistance of OSS signal circuit (Light Green/White wire) between PCM white connector and OSS connector. If resistance 5 ohms or more, repair open OSS signal circuit and perform TEST VER-1A . If resistance is less than 5 ohms, go to next step.
  12. Check resistance of OSS ground circuit (Dark Blue/Black) between PCM White connector and OSS connector. If resistance is 5 ohms or more, repair open OSS ground circuit and perform TEST VER-1A. If resistance is less than 5 ohms, replace OSS and perform TEST VER-1A .
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