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DTC P1320: Ignition Signal: Procedure

  1. Attempt to start engine. If engine starts, go to step  4. If engine does not start, turn ignition off. Disconnect ECCS relay harness connector. See Fig 1. Measure voltage between ground and ECCS relay harness connector terminals No. 2 (White/Blue wire) and No. 7 (White wire). See Fig 2. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See WIRING DIAGRAMS article.
  2. Disconnect ECM harness connector. See Figure. Check continuity of White/Black wire between ECCS harness connector terminal No. 1 and ECM harness connector terminal No. 124. See Figure. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
  3. Using jumper wires, apply battery voltage between ECCS relay terminals No. 1 and 2. See Fig 2. Check continuity between ECCS relay terminals No. 3 and 5. Also, check continuity between ECCS relay terminals No. 6 and 7. Continuity should exist. Remove jumper wires. Continuity should not exist. If continuity is as specified, reconnect all harness connectors and go to step  5. If continuity is not as specified, replace ECCS relay and retest system.
    4. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  4. Using oscilloscope, measure voltage between ground and ECM harness connector terminals No. 43, 44, 46, 47, 50, 51, 53 and 54 to isolate faulty circuit. Each circuit waveform should be as shown in chart. See PIN VOLTAGE CHARTS article. Go to next step.
  5. Turn ignition off. Disconnect ignition coil harness connector(s) of faulty circuit(s). See Fig 3 and Fig 4 . Turn ignition on. Measure voltage between ground and appropriate ignition coil harness connector(s) terminal No. 1 (White/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See WIRING DIAGRAMS article.
  6. Turn ignition off. Loosen and retighten engine ground bolts. See Figure. Check continuity between engine ground and appropriate ignition coil harness connector(s) terminal No. 2 (Black wire). Also, check circuit for short to voltage. See WIRING DIAGRAMS article. Repair circuit as necessary and retest system. If ground circuit is okay, go to next step.
  7. Disconnect ECM harness connector. Check continuity between appropriate ignition coil harness connector(s) terminal No. 3 and appropriate ECM harness connector terminal. See IGNITION COIL/ECM CIRCUIT IDENTIFICATION  table. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
  8. Measure resistance between appropriate ignition coil terminals No. 2 and 3. See Fig 5. If resistance is more than zero ohms, go to next step. If resistance is zero ohms, replace ignition coil and retest system.
  9. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
IGNITION COIL/ECM CIRCUIT IDENTIFICATION

Ignition Coil No. Wire Color ECM Harness Connector Terminal No.
1 Yellow/Red 43
2 Red/Blue 54
3 Gray 47
4 White/Red 53
5 Gray/Red 51
6 Purple/White 50
7 Blue/Red 46
8 Green/Red 44
Fig 1: Locating ECCS Relay
G99D05952Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Identifying ECCS Relay Terminals
G95H31929Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 3: Locating Left Bank Ignition Coils
G97J06695Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 4: Locating Right Bank Ignition Coils
G97B06696Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 5: Testing Ignition Coil
G97F06698Courtesy of NISSAN MOTOR CO., U.S.A.
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