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Home >> Infiniti >> 1995 >> G20 Automatic, 1RL4F03V >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes 2.0L >> Diagnostic Trouble Code (DTC) Testing >> DTC 21: Ignition Signal

DTC 21: Ignition Signal

  1. Check Power Supply

    Start engine. If engine starts, go to step 5). If engine does not start, turn ignition off. Disconnect ignition coil harness connector. Turn ignition on. Measure voltage between ignition coil harness connector terminal "A" (Black/Red wire) and ground. See Fig 1 and Fig 3 . If battery voltage is present, go to next step. If battery voltage is not present, repair Black/Red wire continuity between ignition coil and ignition switch.

  2. Check Ground Circuit

    Turn ignition off. Disconnect power transistor harness connector. Disconnect resistor harness connector. See Fig 1 and Fig 2 . Verify harness continuity between ignition coil connector terminal "B" and power transistor connector terminal "D", and between power transistor connector terminal "H" and engine ground. See Fig 4 and Fig 5 . If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.

  3. Check Output Signal Circuit

    Turn ignition off and disconnect ECM harness connector. Verify harness continuity between ECM terminal No. 1 and power transistor connector terminal "G" (White wire). See Fig 6 . If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.

  4. Check Component

    Inspect ignition coil and power transistor. See BASIC TESTING article. Replace ignition coil and/or power transistor if necessary and perform FINAL CHECK.

  5. Check Input Signal Circuit

    Turn engine off. Disconnect ECM harness connector and strip tape covering resistor. Verify harness continuity between ECM terminal No. 2 and resistor connector terminal "C" (Yellow/Red wire). See Fig 7 . If continuity is present, go to next step. If continuity i s not present, repair harness or connectors as necessary.

  6. Check Component

    Disconnect resistor wiring harness connector. Measure resistance across connector terminals. If about 2200 ohms are present, resistor is okay. Check ECM connector terminals for corrosion or damage. Repair as necessary and perform FINAL CHECK. If about 2200 ohms are not present, replace resistor.

  7. Disconnect ignition coil wiring harness connector. Measure

    resistance across connector terminals. About one ohm should be present. Check power transistor. See BASIC TESTING article. Check ECM connector terminals for corrosion or damage. Repair if necessary and perform FINAL CHECK.
Fig 1: Locating Ignition Coil & Power Transistor Harness Connector (G20)
G95D31867Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Locating Resistor & Harness Connector (G20)
G95E31868Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: DTC 21, Checking Power Supply (G20)
G95F31869Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: DTC 21, Checking Ground Circuit (G20)
G95I31870Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 5: DTC 21, Checking Ground Circuit (G20)
G95J31871Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 6: Checking Output Signal Circuit (G20)
G95A31872Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 7: DTC 21, Checking Input Signal Circuit (G20)
G95B31873Courtesy of NISSAN MOTOR CO., U.S.A.
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