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Home >> Infiniti >> 2002 >> G20 Automatic, RE4F03W >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing - G20 & Q45 >> Ignition System >> Ignition Signal (G20) >> Testing

Ignition Signal (G20): Testing

  1. Turn ignition off. Start engine. Attempt to start engine. If engine is running, go to next step. If engine is not running, go to step  5.
  2. If using CONSULT-II, go to next step. If not using CONSULT-II, go to step  4.
  3. Perform POWER BALANCE in ACTIVE TEST mode with CONSULT-II. If all cylinders produce a momentary engine speed drop, system is okay. If any cylinder does not produce a momentary engine speed drop, go to step  5.
  4. Using an oscilloscope, measure voltage between ground and ECM terminal No. 35 (White/Black wire) by backprobing. See Figure and Figure . Waveform should match waveform shown in illustration. See Fig 1. If waveform is as specified, system is okay. If waveform is not as specified, go to next step.
  5. Turn ignition off. Disconnect distributor 2-pin harness connector (for ignition coil). Turn ignition on. Measure voltage between ground and distributor 2-pin harness connector terminal No. 8 (Green/White wire). If battery voltage exists, go to step  7. If battery voltage does not exist, go to next step.
  6. Check the following:
    • Check for poor connection at White, 18-pin in-line harness connector F23 terminal No. 12 (Green/White wire). See Figure and Figure .
    • Check for poor connection at Super Multiple Junction (SMJ) connector terminal 67K (Red/Black wire). See Figure. SMJ connector is located under left side of instrument panel, behind fuse block.
    • Check ECM relay. See RELAYS  under RELAYS & SOLENOIDS.
    • Check fuse No. 35 (15-amp) located in fuse and fusible link box on left side of engine compartment.
    • Check for open or short between ignition coil and fuse.

    Repair as necessary.

  7. Turn ignition off. Disconnect distributor 6-pin harness connector (for power transistor and CMP sensor). Check continuity between engine ground and distributor 6-pin harness connector terminal No. 5 (Black wire). See Fig 2. Continuity should exist. Also, check circuit for short to voltage. If problem is found, repair as necessary. If circuit is okay, go to next step.
  8. Disconnect ECM harness connector. See Figure. Check continuity of White/Black wire between distributor 6-pin harness connector terminal No. 6 and ECM harness connector terminal No. 35. See Figure. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If circuit is okay, go to next step.
  9. Measure resistance between distributor 2-pin connector terminals. Also, measure resistance between ignition coil tower and distributor 2-pin connector terminal No. 8. See Fig 3. See IGNITION COIL RESISTANCE  table. If resistance is as specified, go to next step. If resistance is not as specified, replace distributor assembly.
  10. To check power transistor, measure resistance between distributor 6-pin connector terminal No. 5 (component side) and distributor 2-pin connector terminal No. 7 (component side). If resistance is zero ohms, replace distributor assembly. If resistance is not zero ohms, go to next step.
  11. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
IGNITION COIL RESISTANCE

Application Resistance @ 77°F (25°C)
Primary (1) About 0.8 Ohm
Secondary (2) About 16K/Ohms
(1) Measured between distributor 2-pin connector terminals.
(2) See Fig 3.
Fig 1: Identifying Ignition Signal Waveform (G20)
G00103757Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Identifying Distributor 6-Pin Connector Terminals (G20)
G00010140Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Measuring Ignition Coil Secondary Resistance (G20)
G00010172Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: Testing Resistor (G20)
G00010176Courtesy of NISSAN MOTOR CO., U.S.A.
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