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NTC-18A: Checking P/N Switch (A/T)

  1. Apply parking brake. Turn ignition on, with engine off. Using scan tool, read Park/Neutral (P/N) position switch input state. Move gear selector in and out of Park and Drive while observing scan tool display. If display corresponds with gear selector position, system is functioning properly. Test is complete. If display does not correspond with gear selector position, go to next step.
    NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
  2. Turn ignition off. Place gear selector in Park. Disconnect Powertrain Control Module (PCM) connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and P/N switch sense circuit. Move gear selector in and out of Park and Drive while observing scan tool display. If resistance stays less than 5 ohms at all times, go to next step. If resistance does not stay less than 5 ohms at all times, repair P/N switch sense circuit for short to ground. Perform TEST VER-2A.
  3. Ensure ignition is off. Ensure PCM connectors are still disconnected. Disconnect P/N switch connector. P/N switch is located on side of transmission. Clean and/or repair connector as necessary. Using ohmmeter, check resistance of P/N switch sense circuit between P/N switch connector and PCM. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open P/N switch sense circuit. Perform TEST VER-2A.
  4. Ensure ignition is off. Ensure PCM connectors are still disconnected. Reconnect P/N switch connector. Using an ohmmeter, check resistance between ground and P/N switch sense circuit. Move gear selector in and out of Park and Drive while observing scan tool display. If resistance switches from less than 5 ohms to more than 5 ohms, replace PCM. Perform TEST VER-2A. If resistance does not switch from less than 5 ohms to more than 5 ohms, go to next step.
  5. At this time, P/N switch is assumed to be defective. Replace P/N switch. Perform TEST VER-2A.
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