Nissan 100NX N14 silhouetteN14

E.C.C. Trouble Diagnoses (Models with catalyzer) - Basic Inspection / Diagnostic Procedure

EF & EC-48prose procedure

Applies to GA13DS, GA14DS & GA16DS engines with catalyzer.

Basic Inspection

  1. 1
    Idle speed: 750 ± 50 rpm
    Basic inspection setup illustration: a tachometer/timing gauge, a timing light pointed at the engine 'Ignition timing' mark, a 'Check connector', a 'CO meter', a 'Test-take off tube'. Note below reads 'Every item should be checked after warming up sufficiently.' with an engine ground/warm-up symbol.
    SEF817L
  2. 2
    Ignition timing: 10° ± 2° B.T.D.C.
  3. 3
    Idle CO: 1.0 ± 0.5% (test-take off tube). • A.I.V. control solenoid valve harness connector disconnected (No A.I.V. controlled condition). • Exhaust gas sensor harness connector disconnected.
  4. 4
    Air-fuel ratio at approximately 2,000 rpm of engine speed. Number of fluctuations of voltage meter: 5 times or more/10 seconds (Refer to section MA.)
  5. 5
    Engine speed of idle switch OFF → ON: 1,200 rpm

Diagnostic Procedure

Diagnostic Procedure - CAUTION

  1. 1
    Before connecting or disconnecting E.C.U. harness connector to or from any E.C.U., be sure to turn the ignition switch to the "OFF" position and disconnect the negative battery terminal in order not to damage E.C.U. as battery voltage is applied to E.C.U. even if ignition switch is turned off. Otherwise, there may be damage to the E.C.C.S. control unit.
    Battery voltage is applied to E.C.U. even if ignition switch is turned off.
    Illustration of the E.C.U. (E.C.C.S. control unit) showing a harness connector being attached, illustrating proper handling when connecting or disconnecting the harness.
    SEF036E
  2. 2
    When connecting pin connectors into E.C.U. or disconnecting them from E.C.U., take care not to damage pin terminal of E.C.U. (Bend or break).
    Illustration of E.C.U. pin connectors with two damaged pins labeled 'Bend' and 'Break', warning against damaging the pin terminals when connecting.
    SEF329D
  3. 3
    Make sure that there are not any bends or breaks on E.C.U. pin terminal, when connecting pin connectors into E.C.U..
  4. 4
    Before replacing E.C.U., perform E.C.U. input/output signal inspection and make sure whether E.C.U. functions properly or not. (See page EF & EC-136.)
    Cartoon of a person holding an 'OLD ONE' E.C.U. with a speech bubble reading 'Perform E.C.U. input/output signal inspection before replacement.', illustrating verifying E.C.U. function before replacement.
    SEF330D
  5. 5
    After performing this "Diagnostic Procedure", perform driving test.
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See also

MA sectionEF & EC-136E.C.C. TROUBLE DIAGNOSES (Models with catalyzer) — Electrical Components Inspection: E.C.C. Control Unit Input/Output Signal Inspection

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