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Pathfinder & QX4

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step  12. If engine does not start, go to step  3.
  2. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. If engine speed drops as each cylinder is tested, testing is complete. If engine speed does not drop as each cylinder is tested, go to step  12.
  3. Turn ignition off, wait 10 seconds and turn ignition on. Backprobing at ECM, measure voltage between ground and ECM harness connector terminals No. 110 and 112 (Black/White wire). See Figure. If battery voltage exists, leave ignition on and go to next step. If battery voltage does not exist, check power supply for ECM. See POWER & GROUND CIRCUITS (PATHFINDER & QX4)  under COMPUTERIZED ENGINE CONTROLS.
  4. Turn ignition off. Disconnect ignition condenser 2-pin harness connector. Condenser is located on wiring harness along side of intake manifold collector, near vacuum reservoir. Turn ignition on. Measure voltage between ground and ignition condenser harness connector terminal No. 1 (Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, leave harness connector disconnected and go to step  10.
  5. Turn ignition off. Disconnect ECM relay from underhood fuse and relay panel. For ECM relay location, see Figure. Check continuity of Red wire between ECM relay and ignition condenser. See WIRING DIAGRAMS article. Also, check circuit for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, leave ECM relay disconnected and go to step  7.
  6. Check following:
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E1 and M1. See WIRING DIAGRAMS article.
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors F22 and M33.
    • Check for open or short in circuit between ECM relay and ignition condenser.
    If problem is found, repair as necessary. After repair, retest system.
  7. Measure voltage between ground and ECM relay harness connector terminal No. 5 (Red/White wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step  9.
  8. Check following:
    • Check fuse block fuse No. 63 (10-amp).
    • Check for open or short in circuits between ECM relay and fuse. See WIRING DIAGRAMS article.
    If problem is found, repair as necessary. After repair, retest system.
  9. Working with ECM relay, apply battery voltage and ground to terminals No. 1 and 2. See Figure. When battery voltage is applied, continuity should exist between terminals No. 3, 5, 6 and 7. When battery voltage is removed, continuity should not exist. If relay tests okay, go to next step. Replace relay, if test values are not as specified.
  10. Turn ignition off. Measure resistance in Black wire between ground and ignition condenser harness connector terminal No. 2. Continuity should exist. Also, check circuit for short to voltage. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  11. Check condenser. See IGNITION CONDENSER . If no problem is found, go to next step. If problem is found, replace condenser.
  12. Turn ignition off. Connect any disconnected harness connectors. Disconnect suspect ignition coil 3-pin harness connector. Turn ignition on. Measure voltage between ground and suspect ignition coil harness connector terminal No. 3 (Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step  14.
  13. Check for open or short between suspect ignition coil and in-line harness connector F22. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair, retest system.
  14. Turn ignition off. Check continuity of Black wire between ground and suspect ignition coil harness connector terminal No. 2. See Figure. Continuity should exist. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, retest system.
  15. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure. Check continuity between ignition coil terminal No. 1 and ECM harness connector terminals No. 21, 22, 23, 30, 31 and 32. See Figure and Figure . Continuity should exist at each measurement. Also, check circuits for short to ground or short to voltage. If problem is found, go to next step. If no problem is found, go to step  17.
  16. Check ignition coil with power transistor. See IGNITION COIL WITH POWER TRANSISTOR . If no problem is found, go to next step. If problem is found, replace suspect ignition coil. After repair retest system.
  17. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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