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Home › Jeep › 1999 › Cherokee Sport, 2D Utility, 4WD, Part Time, Standard › Repair and Diagnosis › Engine Performance › System › Engine Controls - Tests W/Codes › No-Start Tests › Test NS-6A: Repairing No Response Condition

Test NS-6A: Repairing No Response Condition

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
  1. Turn ignition off. Disconnect Powertrain Control Module (PCM) Black connector. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connector as necessary. Using a voltmeter, check voltage on PCM Black connector, fused B+ circuit. If voltage is more than 10 volts, reconnect PCM Black connector and go to next step. If voltage is 10 volts of less, go to step 17).
  2. Ensure ignition is off. Using voltmeter, backprobe Throttle Position (TP) sensor connector, 5-volt supply circuit. TP sensor is located on throttle body. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, go to step 13).
  3. Ensure ignition is off. Disconnect TP sensor connector. Clean and/or repair connector as necessary. Turn ignition on, with engine off. Using voltmeter, check voltage on TP sensor connector, sensor ground circuit. If voltage is more than one volt, repair sensor ground circuit for short to voltage. Perform TEST VER-1A. If voltage is one volt or less, go to next step.
  4. Turn ignition off. Ensure TP sensor connector is still disconnected. Turn ignition on, with engine off. Connect voltmeter between ground and TP sensor connector, 5-volt supply circuit. Disconnect Camshaft Position (CMP) sensor connector. Clean and/or repair connector as necessary. Read voltmeter. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, replace CMP sensor. Perform TEST VER-1A.
  5. Turn ignition off. Ensure TP sensor connector is still disconnected. Turn ignition on, with engine off. Check voltage on TP sensor connector, 5-volt supply circuit. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, replace TP sensor. Perform TEST VER-1A.
  6. Turn ignition off. Ensure TP sensor connector is still disconnected. Turn ignition on, with engine off. Connect voltmeter between ground and TP sensor connector, 5-volt supply circuit. Disconnect Crankshaft Position (CKP) sensor connector. Clean and/or repair connector as necessary. Read voltmeter. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, replace CKP sensor. Perform TEST VER-1A.
  7. Turn ignition off. Ensure TP sensor connector is still disconnected. Turn ignition on, with engine off. Connect voltmeter between ground and TP sensor connector, 5-volt supply circuit. Disconnect transmission solenoid connector (if equipped). Clean and/or repair connector as necessary. Read voltmeter. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, replace transmission governor/pressure sensor. Perform TEST VER-1A.
  8. Turn ignition off. Ensure TP sensor connector is still disconnected. Turn ignition on, with engine off. Connect voltmeter between ground and TP sensor connector, 5-volt supply circuit. Disconnect MAP sensor connector. Clean and/or repair connector as necessary. Read voltmeter. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or more, replace MAP sensor. Perform TEST VER-1A.
  9. Turn ignition off. Disconnect PCM connectors. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and PCM connector, 5-volt primary supply circuit. If resistance is less than 5 ohms, repair 5-volt primary supply circuit for short to ground. Perform TEST VER-1A. If resistance is 5 ohms or more, go to next step.
  10. Ensure ignition is off. Ensure PCM connectors are still disconnected. Using a voltmeter, check voltage on PCM connector, fused ignition switch output circuit. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open fused ignition switch output circuit. Perform TEST VER-1A.
  11. Turn ignition off. Ensure PCM connectors are still disconnected. Using an ohmmeter, check resistance between ground and both PCM connector, ground circuits. If resistance is less than 5 ohms on both ground circuits, go to next step. If resistance is 5 ohms or more on either ground circuit, repair open ground circuit(s). Perform TEST VER-1A.
  12. Ensure ignition is off. Ensure PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, 5-volt secondary supply circuit. If resistance is less than 5 ohms, repair 5-volt secondary supply circuit for short to ground. Perform TEST VER-1A. If resistance is 5 ohms or more, perform TEST NS-6C: REPAIRING NO RESPONSE CONDITION.
  13. Ensure ignition is off. Disconnect TP sensor connector. Clean and/or repair connector as necessary. Using voltmeter, check voltage on TP sensor connector, 5-volt supply circuit. If voltage is more than 5.5 volts, repair 5-volt supply circuit for short to voltage. Perform TEST VER-1A. If voltage is 5.5 volts or less, go to next step.
  14. Ensure ignition is off. Ensure TP sensor and PCM Black connectors are still disconnected. Turn ignition on, with engine off. Using voltmeter, check voltage on PCM connector, fused ignition switch output circuit. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open PCM connector ground circuit(s). Perform TEST VER-1A.
  15. Turn ignition off. Ensure PCM Black connector is still disconnected. Using an ohmmeter, check resistance between ground and both PCM Black connector, ground circuits. If resistance is less than 5 ohms on both ground circuits, go to next step. If resistance is 5 ohms or more on either ground circuit, repair open ground circuit(s). Perform TEST VER-1A.
  16. At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-1A.
  17. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Turn ignition on, with engine off. Using a voltmeter, check voltage on PCM Black connector, fused ignition switch output circuit. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open fused ignition switch output circuit. Perform TEST VER-1A.
    NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
  18. Turn ignition off. Remove and inspect fuse in Power Distribution Center (PDC) that supplies fused B+ voltage to PCM connector C1, terminal A22. PDC is located next to battery. If fuse is defective, go to next step. If fuse is okay, go to step 21).
  19. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Using an ohmmeter, check resistance between ground and both PCM connector, ground circuits. If resistance is less than 5 ohms on both ground circuits, go to next step. If resistance is 5 ohms or more on either ground circuit, repair open ground circuit(s). Perform TEST VER-1A.
  20. Ensure ignition is off. Remove fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22. Using a voltmeter, check voltage on B+ side of fuse connector. If voltage is more than 10 volts, repair open B+ circuit from fuse to PCM. Perform TEST VER-1A. If voltage is 10 volts or less, repair B+ circuit from fuse to battery. Perform TEST VER-1A.
  21. Turn ignition off. Ensure PCM Black connector is still disconnected. Using an ohmmeter, check resistance between ground and both PCM connector, ground circuits. If resistance is less than 5 ohms on both ground circuits, go to next step. If resistance is 5 ohms or more on either ground circuit, repair open ground circuit(s). Perform TEST VER-1A.
  22. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Remove fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22. Remove ASD and fuel system relays (if equipped). ASD and fuel system relays are located in PDC. Refer to label under PDC cover for relay location. Clean and/or repair connectors as necessary. Using ohmmeter, check resistance between ground and ASD relay connector, ASD relay output circuit. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, go to step 30).
  23. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD and fuel system relays (if equipped) are still removed. Using ohmmeter, check resistance between ground and PCM connector, fused B+ circuit. If resistance is less than 5 ohms, repair fused B+ circuit for short to ground and replace fuse. Perform TEST VER-1A. If resistance is 5 ohms or more, go to next step.
  24. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD relay is still removed. Disconnect HO2S connectors. Using ohmmeter, check resistance between ground and ASD relay output circuit at each HO2S connector. If resistance is 5 ohms or less on all ASD relay output circuits, go to next step. If resistance is more than 5 ohms on any ASD relay output circuit, repair ASD relay output circuit(s) or replace defective HO2S, and replace fuse. Perform TEST VER-1A.
  25. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD relay is still removed. Ensure HO2S connectors are still disconnected. Disconnect Generator (GEN) field connector. See Figure. Using ohmmeter, check resistance between ground and ASD relay connector, output circuit. Monitor resistance while disconnecting each fuel injector connector. If resistance goes to more than 5 ohms when disconnecting fuel injectors, go to next step. If resistance does not go to more than 5 ohms when disconnecting fuel injectors, repair ASD relay output circuit(s) for short to ground, and replace fuse. Perform TEST VER-1A.
  26. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD relay is still removed. Ensure HO2S and GEN field connectors are still disconnected. Using ohmmeter, check resistance between ground and ASD relay connector, output circuit. Monitor resistance while disconnecting each ignition coil connector. If resistance goes to more than 5 ohms when disconnecting ignition coils, replace ignition coil(s), and replace fuse. Perform TEST VER-1A. If resistance does not go to more than 5 ohms when disconnecting ignition coils, go to next step.
  27. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD relay is still removed. Ensure HO2S and GEN field connectors are still disconnected. Using ohmmeter, check resistance between ground and ASD relay connector, output circuit. If resistance is more than 5 ohms, repair or replace generator and replace fuse. Perform TEST VER-1A. If resistance is 5 ohms or less, go to next step.
  28. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD relay is still removed. Ensure HO2S and GEN field connectors are still disconnected. Using ohmmeter, check resistance between ground and ASD relay connector, output circuit. Monitor resistance while disconnecting Leak Detection Pump (LDP) connector. If resistance goes to more than 5 ohms when disconnecting LDP connector, replace LDP, and replace fuse. Perform TEST VER-1A. If resistance does not go to more than 5 ohms when disconnecting LDP connector, go to next step.
  29. At this time, fuel injector is assumed to be defective. Replace fuel injector that causes a change in resistance and replace fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22. Perform TEST VER-1A.
  30. Ensure ignition is off. Ensure PCM Black connector is still disconnected. Ensure fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22 is still removed. Ensure ASD and fuel system relays (if equipped) are still removed. Using ohmmeter, check resistance between ground and PCM connector, fused B+ circuit. If resistance is less than 5 ohms, repair fused B+ circuit for short to ground, and replace fuse. Perform TEST VER-1A. If resistance is 5 ohms or more, go to next step.
  31. Ensure ignition is off. Disconnect fuel pump connector. Fuel pump is located in fuel pump module. Fuel pump module is located in fuel tank. Using ohmmeter, check resistance between ground and fuel pump connector, fuel pump relay output circuit. If resistance is less than 5 ohms, repair fuel pump relay output circuit for short to ground and replace fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22. Perform TEST VER-1A. If resistance is 5 ohms or more, go to next step.
  32. At this time, fuel pump is assumed to be defective. Replace fuel pump and replace fuse in PDC that supplies fused B+ voltage to PCM connector C1, terminal A22. Perform TEST VER-1A.
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