LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 2002 >> Sentra SE-R, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing - 4 CYL & V6 >> Miscellaneous Controls >> Electrical Load Signal >> Sentra (1.8L)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Sentra (1.8L)

  1. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (SENTRA)  table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step  7.
    CHECKING REAR WINDOW DEFOGGER LOAD SIGNAL (SENTRA)

    Condition Load Signal
    Rear Window Defogger Switch ON ON
    Rear Window Defogger Switch OFF OFF
  2. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA)  table. If LOAD SIGNAL parameter displays as specified, go to next step. If parameter is not as specified, go to step  8.
    CHECKING LIGHTING SWITCH LOAD SIGNAL (SENTRA)

    Condition Load Signal
    Lighting Switch ON At First Or Second Position ON
    Lighting Switch OFF OFF
  3. Turn ignition on. Using CONSULT-II in DATA MONITOR mode, observe LOAD SIGNAL parameter under following conditions. See CHECKING FAN CONTROL SWITCH LOAD SIGNAL (SENTRA)  table. If LOAD SIGNAL parameter displays as specified, go to step  16. If parameter is not as specified, go to step  9.
    CHECKING FAN CONTROL SWITCH LOAD SIGNAL (SENTRA)

    Condition Load Signal
    Fan Control Switch ON ON
    Fan Control Switch OFF OFF
  4. If CONSULT-II is not available. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM terminal No. 50 (Red/White wire). See Figure and Figure . With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step  7.
  5. If CONSULT-II is not available. Backprobing at ECM, measure voltage between ground and ECM terminal No. 50 (Red/White wire). With lighting switch On in second position, battery voltage should exist. With lighting switch Off, zero volts should exist. If voltage is as specified, go to next step. If voltage is not as specified, go to step  8.
  6. If CONSULT-II is not available. Backprobing at ECM, measure voltage between ground and ECM terminal No. 51 (Light Green/Black wire). With blower fan on, battery voltage should exist. With blower fan off, zero volts should exist. If voltage is as specified, go to step  16. If voltage is not as specified, go to step  9.
  7. Start engine. Turn rear window defogger on. If rear window warms up, go to step  10. If rear window does not warm up, repair rear window defogger. See appropriate REAR WINDOW DEFOGGERS article in ACCESSORIES & EQUIPMENT.
  8. Start engine. Turn headlights on. If headlights illuminate, go to step  12. If headlights do not illuminate, repair lighting system. See HEADLIGHT SYSTEMS article in ACCESSORIES & EQUIPMENT.
  9. Start engine. Turn heater fan on. If fan motor operates, go to step  14. If fan motor does not operate, repair blower motor. See appropriate MANUAL OR AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  10. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure. Disconnect rear window defogger relay harness connector. See Figure. Connect positive DVOM lead to ECM harness connector terminal No. 50 (Red/White wire) and negative DVOM lead to rear window defogger relay harness connector terminals No. 5 and 7 (Blue/Red wires) and check continuity. See Figure and Figure . Continuity should exist. Reverse DVOM leads and check continuity. Continuity should not exist. 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  16.
  11. Check following:
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors B1 and M14. See WIRING DIAGRAMS article.
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26.
    • Check for poor, loose, corroded or damaged terminal connections in diode M55.
    • Check for open or short in circuits between ECM and rear window defogger relay.
    If problem is found, repair as necessary. After repair, retest system.
  12. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure. Disconnect combination switch harness connectors (headlight switch). Connect positive DVOM lead to ECM harness connector terminal No. 50 and negative DVOM lead to combination switch harness connector terminal No. 12 (Red/White wire at ECM changes to White/Red wire at combination switch), and check for continuity. Continuity should exist. Reverse DVOM leads, and check for continuity. Continuity should not exist. See WIRING DIAGRAMS article. 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  16.
  13. Check following:
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M58 and F26. See WIRING DIAGRAMS article.
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors E108 and M19.
    • Check for poor, loose, corroded or damaged terminal connections in fuse block harness connectors M1 and E103.
    • Check for poor, loose, corroded or damaged terminal connections in diode M52.
    • Check for poor, loose, corroded or damaged terminal connections in diode M55.
    • Check for open or short in circuits between ECM and combination switch.
    If problem is found, repair as necessary. After repair, retest system.
  14. Turn ignition off. Disconnect ECM 116-pin harness connector. For ECM location, see Figure. Disconnect heater fan control switch harness. Check continuity of Light Green/Black wire between heater fan control switch harness connector terminal No. 6 and ECM harness connector terminal No. 51. See WIRING DIAGRAMS article. Check continuity of Black wire between ground and heater fan control switch harness connector terminal No. 5. Continuity should exist at both measurements. Also, check circuits for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step  16.
  15. Check following:
    • Check for poor, loose, corroded or damaged terminal connections in in-line harness connectors M59 and F27. See WIRING DIAGRAMS article.
    • Check for open or short in circuits between ECM and fan control switch.
    • Check for open or short in circuits between body ground and fan control switch.
    If problem is found, repair as necessary. After repair, retest system.
  16. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
scientia non olet · About LEMON Manuals