Code 15 - Ignition Output Signal

Turn ignition off. 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.
If light is on, turn ignition off. Disconnect 4-wire connector on ignitor unit. Turn ignition on. Using a voltmeter, measure voltage between Red/Blue (pos.) wire terminal and Black (neg.) terminal.
If battery voltage exists, proceed to step 4). If battery voltage does not exist, measure voltage between Red/Blue terminal and 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.
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.
If battery voltage exits, substitute a known good ECU. Connect system checker harness between ECU and ECU connector. Reconnect 4-wire ignitor connector. Turn ignition on. Individually, measure voltage between ECU terminals B15 (pos.), B16 (neg.), and A18 (ground).
If battery voltage exists, substitute a known good ECU and recheck. If condition is rectified, replace original ECU. If battery voltage does not exist, turn ignition off. Disconnect connector from ignitor unit and system checker harness from ECU Check continuity of Red/Blue wire between ECU and ignitor unit.
If no continuity exists, repair open in Red/Blue wire. If continuity exists, check continuity to body ground and Red/Blue wire on ignitor unit 4-wire connector.
If no continuity exists, replace ignitor unit. If continuity exists, repair short in Red/Blue wire and/or replace ignitor unit.