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Code 15, Ignition Output Signal

  1. Turn ignition off and disconnect alternator sense fuse in under-hood relay box for 10 seconds to reset ECU. Start engine and observe PGM-FI warning light. If light is off, problem is intermittent. Test drive and check again.
  2. If light is on, turn ignition off. Disconnect 4-wire connector on ignitor unit. Turn ignition on. Using a voltmeter, measure voltage between Blue (pos.) terminal and Black (neg.) terminal.
  3. If battery voltage exists, proceed to step 4). If no battery voltage exists, measure voltage between Red/Blue terminal and body ground. If battery voltage still does not exist, repair open in Red/Blue wire. If battery voltage does exist, repair open in Black wire between ignitor unit and ground.
  4. If battery voltage is present, measure voltage between Black/Yellow (pos.) Black (neg.) terminals of ignitor unit connector. If battery voltage exists, proceed to step 5). If no battery voltage exists, repair Black/Yellow wire between ignitor unit and ignition switch.
  5. If battery voltage exists, turn ignition off. Connect system checker harness between ECU and ECU connector. Reconnect ignitor 4-wire connector. Turn ignition on. Measure voltage individually between terminal A18 (neg.) and terminals B15 and B16.
  6. If battery voltage exists, substitute a known good ECU. If condition is rectified, replace original ECU. If no battery voltage exists, disconnect connector from ignitor unit and system checker harness from ECU. Check for continuity of Red/Blue wire between ECU and ignitor unit.
  7. If no continuity exists, repair open in Red/Blue wire. If continuity exists, check for continuity to body ground and Red/Blue wire on ignitor unit connector.
  8. If no continuity exists, replace Ignitor unit. If continuity exists, repair short in Red/Blue wire and/or replace ignitor unit as unit may be broken internally.
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